SCIENCE. 227 · SCIENCE. theformationofrainunderthese circumstances seems disproved, in another...

SCIENCE.

the formation of rain under these circumstancesseems disproved, in another place, by theauthor himself, who rejects the theory that anlyconsiderable precipitation can be produced bythe mixture of masses of hot and cold air.Mr. Scott acknowledges that nothing definiteis known as to the origin of atmiospheric elec-tricity; but his conjecture that the coalescenceof cloud-droplets into rain-drops may be dueto electricity will hardly be accepted by mete-orologists at present. The description of a

peculiar electrical manifestation observed inthe Alps, July 10, 1863, is very similar to thatgiven bv Siemens while on Cheops pyramid,April 14, 1859.The division of thunder-stornms into heat

aind cyclonic is hardly applicable to the UnitedStates, where it appears as if no thunder-storms occur, except as largely influenced by,or directly clependent on, the presence of a

barometric depression.The error of more than forty million square

227

miles in the earth's surface between the equa-

tor anid 300 north latitude should be correctedin the next edition.

Thie statement, that at great depths in theocean a probable uniform temperature of 320 F.prevails, has been disproved by the researchesof Professor Verrill and the U. S. fish-com-missioni.We notice on p. 362 the surprising state-

ment, that, as the central office of the U. S.weather bureau is in the eastern part of thecountry, there is a great advantage to thosepredicting storims by the use of the tele-graph.The chart of mean January isobars does

not incorporate Stelling's work in Siberia,published in 1870, and accepted by Mohnin the last edition of his Meteorology. Mohin'schart shows a mean pressure over central Si-beria of 780 mm. (30.79 in.), while the highestfigure in Scott for the same region is 30.4inches.

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE.THE thirty-secoud aninual meeting of the

American association was opened in the hallsof the uniiversitv of Minnesota, Minneapolis,Aug. 15, at 10.30 A.M. Dr. J. W. Dawson,the etiring president, introduced the presi-dent elect, Prof. C. A. Young, who brieflyand gracefully expr essed his thanks to theassociation for the distinctionl they had offeredhim. After welcomes spoken by the governorof the state and the mayor of the city, theprincipal address was made by thle actingpresident of the university, Dr. W. W. Folwell,on behalf of the local committee. From hisaddress we print the closing sentences:

I should do a wrong to my city if I should leave

upon you the impression that we are so overwhelmedan(d engrossed with our material labors as to have no

care for the things of the mind and the higher life.

If that were truie, why should we welcome with so

much sincere ardor the assemblage of your associa-

tion ? From the villages of New Enigland, and thefarmhouses of the Middle states. our people havebrouight that perennial curiosity, that thirst for

knowledge, that intense though sombre imagiination,which have given Americani civilization and Amnericanliterature a cast and hue of its own. I must, in a

word, praise our system of public schools, both cityand state, which under able management and popu-lar support cannot, we believe, be ranked below those

of any commuinities of our size in the Union. Minne-

sota is the first place which has organized its second-ary as well as its primary education, anid offeredl to

every child in the state a free course of stuidies, fromthe alphabet to the degree of master of arts. Ouirchurches, goodly in size and number, may speak forthe interests of religion. The future will attest thediligence and the fidelity of those who love musicand the sister arts, of whom far older cities might beproud. It is thus, however, Mr. President, that we

Minneapolitans, alert, pre-occupied, pause in the midstof our labors to welcome your already venerable asso-

ciation. We hail you as the survivors of a generationof great investigators, -the Sillimans, the Baches,the Morses, the Rogerses, who hiave made their owncountry famous and their own names as imperishableas science herself. We hail you as the worthy suc-

cessors of such a generation, perpetuating and enlar-ging their work. In commnon with civilized people, werecognize the immense debt of the modern world toscience; yet often, no doubt, while we are filling thesky with applause to some lucky inventor, we are notremembering the years, perhaps generations, of incon-spicuous and painful labors, carried on in our studiesaaid laboratories, which made the invention possible.Let the inventor have his glory and his proflt withoutenvy and without stint; but let us not fail to buildthe cenotaph of a thousand nameless geometers, star-gazers, and natural plilosophers, who, working insilence and obscurity, without thought of fame or

hope of reward, put it in his power to bless and capti-vate the world. We are grateful, therefore, to sciencefor the telegraph and the microscope, for chloroform,for the photograph, for all the nameless applicationsof electricity. To science we owe that magnificentapparatus of transportation which Is the crowningand distinctive feature of modern material life. To

AUGUST 24, 1883.1

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science we owe the thousand appliances which yieldcomfort and even elegance to the humblest house-hold. Immense as are these contributions of scienceto material comfort and happiness, she has still, Ithink,, performed greater services to mankinid. Thescienitific method developed in the study of naturehas spread to all branches of investigation. It haspermeated all our education: it has boldly leaped theboundary between physics and metaphysics. It haseven penetrated into industry and business anid com-mon life. The modern man first collects what knowl-edge he can about his enterprise or adventure, andassures himself of its value. He then makes the bestquest he can in regard to the future. Then he as-sembles new facts, and, as the facts requiire, revisesand amends his theory, till at length it becomes aworking rule, maxim, and principle. He knows notmerely how to know, but how to guess. The pene-tration of the scientific method int6 the operations oftrade in great commercial centres is very conspicuous.We even endeavor to gamble scientifically. No Drew,or Armour, or Gould ever forms his cornier without amost careful study of the situation; and his ventureis his bet on the correctness of his theory. Thefarther extension of the scientific method, till itshall become the guide of conduct in the every-daylife of all men, is now the chief problem in educa-tion.

In the next place, I think science may at lengthfairly claim to have wrought out, under great diffi-c4lties, a working hypothesis of our universe in thenebular hypothesis and its almost necessary corollary,'evolution.' It cannot be denied that we are all,in somne sense, evolutionists, - some of us againstour prepossessions, some of us by insensible butprogressive lapses. I am not competent to argue outthis great theme. I feel bouind to admit that theevolution doctrine, in one form or other, has quietlytaken posp.ession of the modern mind. Why nay wenot gladly accept it as a most useful working hy-pothesis of the mode of creation ? I say, of the modeof creation; for the mystery of creation will forevermock the powers of man. Only this we know: thatunless human consciousness is a juggle, and humanlanguage a mockery, there can niever be to mani acreation without a creator, nor an evolution withoutan evolver.

Another great service of sciepce is the mainte-nance in the world of a body of men, a lay priest-hood, devoted to the search for truth for its ownsake and its own value. In a mercenary age, when,in the opinion of a distinguished contemporary,mercantilism has become a huge disease and excres-cenice on society, the example of such a body of menis of supreme value in the training of the niew gener-ations. Youth are formed, a wise Greek has taughtus, not so much by schools as by the example of dis-tinguished men.

A, still greater benefit of science tb mankind is theemancipation it ha9 wrought for us, in the last genera-tion, from superstition and the dominion of imagi-nary powers. It is no long time since it was generallybelieved by civilized men, that human affairs were

[VOL. II., No. 29.

under the control of the spirits of the air, good orevil. Men walked in cringing terror, by day andnight, of demons and goblins damned. The earth-quake, the torniado, the lightning's stroke, theylooked upon as instruments of punishment for thesins of rulers and peoples. Thanks to science, themoderin world has emerged from this cloud of gloom.We have some certain knowledge. Knowledge is niotmerely qualitative, but quantitative. Truth evermakes free. Above all, we know that all things innature are governied by law,- law, " whose seat is inthe bosom of God, whose voice is the harmony of theworld." The beautiful conception of the Greeks ofthe universe as a kosmos, that is, an embodimiient ofdivine and perfect order, is pervading modern thought.We now know that the phenomena of nature have norelation to human coniduct, the impartial rain fallingalike onl the just and unjust. Men walk the eartherect and free, fearing no bogies, or warlocks, ordemons of any kind. How vast and how blessed therelief to childhood ! In dispellinig superstition, sci-ence has inicidentally wrought her greatest service tomankind in the purifieation of religiou. The time iscoming when grateful thammks will be rendered by themiinister of religion for the emancipation wlhich sci-ence has wrouglht for tbe faith; wlhen the conflict ofscience and religion will onlly be remembered as theantagoutism of crude theories on the one hand, andcruder superstitionis on the other. Grateful we arefor the knowledge which science has collected andcollated and perpetuated to our use. All hoonor tothe men who are consecrated to truth in her service!We inay not ki-mow what marvels, far surpassing allthe gifts of the past, the sc;ience of the future mnayre'veal. Still, we must remember that the humanmind is finite, while truth is infinite. The vast un-knowjn engirdles our little circle of light. The mys-tery of life anid death, no son of earth has everpenetrated. Welcome, then, the faith which pointsto the contiluance of life in a lanid where study willbe no weariness to the soul, where no veil offileshwill cloud the vision, where scienice and religion shallbe forever one, where men shall know even as theywere known.To welcome you as a body of scientists, lovers

and seekers after truth from love of it and of youtrkind, would be well worth our while, were it ouronly motive to improve and inspire the children andyouth of our city. In doinig you honor, we givethem'a lesson no books nor masters could impart.For their sake we renew our welcome.

President Young briefly responded:-GENTLEMEN, -On behalf of my fellow-members

of the association, I return you my sincerest thanksfor the hearty welcome we have received to this mnag-nificent state, this young and beautiful city, this vig-orous, energetic, warm-hearted community. Whenyou first invited us here, it was not in our power tocome; buit your second invitation we have acceptedmost gladly, and hope and believe that our meetinghere will prove a benefit and pleasure to all con-

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cernied. Somne of us have known you personally be-fore, and most of us have long been more or lessfamiliar at seconid hand with your state and city;and yet, I think, to many of us it is somethingf likea new revelation to see for ourselves what a fewyears have accomplished. I am not enough of aLatin scholar to quote my Virgil well; but I havebeen all the time most forcibly reminded of the pas-sage in which Aneas first comes in sight of risingCarthage. Most emphatically the work ' hails'here. We see no drones or sluggards; but everyshoulder is at the wheel, and every thing is moving.It may, perhaps, seem to you sometimes, when in oursectional meetings we discuss some question aboutthe stars, or some hypothesis as to the formation ofrock-strata, or the structuire of some worm or insect,that we are out of the current, and contributing'nothing to the advancement of the world. But youknow it is not so, and your invitation to hold ourmeeting here shows that you know it. The worldadvances, not on one line only, but oni many, -onlines material, intellectutal, spiritual. To some ex-tenit, the movements are indeed iindependent, butinot very far. Any true advance on either line im-plies corresponding movement on each of the others,

NCE. 229

if not absolutely simuiltaneous, yet surely consequent.There is no need to ask you here how much this cityowes to moderni scienice, wheni I see on every side, inyouir streets and storehouses and mills, the practicalapplication of the hi,ghest engineering, mechanical,and electric art; and in the future it is almost certainthat scienice is to contribute still more liberally tobusiness. But not mainly for this reason do I claimyour regard to science; but because, inade in the im-age of God as we are, knowledge and understandingare as truly wealth and power as lands and food andmoney.

I need not add that, as you have invited us here, sowe on our part cordially invite you to attend all ouirmeetings, to listen to the papers and their discus-sion. We cannot promise that every paper will beinteresting to all, but each one, I think, will be ableto select certain ones he will be glad to hear; anid ifany of you choose to join us, and enroll yourselves aspromoters of the advancement of science, our mem-bership is open on easy terms. Once more, genitlemen,we thank you for the cordial welcome, and addressourselves to our buisiness, in the hope and confidencethat our meeting here is to be in the highest degreepleasant and successful.

PROCEEDINGS OF SECTION A. -MATHEMATICS AND ASTRONOMY.

ADDRESS OF WILLlAM A. ROGERS,OF CAMBRIDGE, MASS., VICE-PRES!-DENVT OF THE SECTION, AUG. 15, 1883.

THE GERMAN SURVEY OF THE NORTH-ERN HEAVENS.

THE illustrious Argelander was accustomed to say,in the quaint form of speech which he often em-

ployed, "The attainable is often not attained if therange of inquiry is extended too far." In no uinder-takillg is there greater need of a judicious applicatiniof this sound maximn than in the systematic determi-nation of the exact positions of all the stars in thevisible heavens wlich fall within the reach of tele-scopes of moderate power.The first subject which engaged the attention of

the Astronomische gesellschaft, at its fornation in

1865, was the proposition to determine accurately theco-ordinates of all the stars in the northern heav-

ens down to the ninth magnitude. To this associa-tion of astronomers (at first nationial, but sincebecome largely international, in its character and or-

ganization) belongs the credit of arranging a schemeof observations by whicih, through the co-operation ofastroinomers in different parts of the world, it hasbeen possible to accomplish the most important pieceof astronomical work of modern times. With a fea-sible plan of operations, undertaken with enitire unityof purpose on the part of the observers to whom theseveral divisions of the labor were assigned, this greatwork is now apprbaching completion. While it is yettoo early to speak with confidence concerning the

definitive results which the discussion of all the ob-

servations are expected to show, we may with profitconsider the object sought in the undertaking, thegeneral plan of the work, the difficulties wlichl havebeen encountered, and the probable bearing whichthe execution of the present work will have upon thesolutioni of a problem concerning whiclh we nowknow absolutely nothing with certainty, -a problemof wlhich what we call universal gravitation is onlyonie element, if, indeed, it be an element, -a problemwhich reaches fartlher than all others into the mys-teries of the universe, -the motion of the solar andthe sidereal systems in space.Our first inquiry will be with respect to the con-

dition of the question of stellar positions at the timewlhen this proposal was made by the gesellschaft in1865. All the observations which had been made upto this time possess one of two distinct characteris-tics. A portion of them were made withouit directreference to any assumed system of stellar co-ordi-nates as a base, but by far the larger part are differ-ential in their character. This remark holds moreespecially witli reference to right ascensions. Nearlyall of the observations of the brighter stars made pre-vious to about 1830 were referred to the origin fromwhich stellar co-ordinates are reckoned by correspond-ing observations of the sun; but since that date it hasbeen the custom to select a stufficient number of ref-erence stars, symmetrically distributed both in rightascension and declination, and whose co-ordinateswere supposed to be well known. The unequalledPulkova observations for the epoch 1845 form, I be-lieve, the only exception to this statement. From theassumed system of primary stars are derived the clockerrors and instrumental constants which are employed

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in the reduction of all the other stars observed. Thepositions of these secondary stars, therefore, partakeof all the errors of the assumed fundamental sys-tem, in addition to the direct errors of observation.The following list comprises the most important

of the catalogues which have been independentlyformed; viz., Bessel's Bradley for 1755, the variouscatalogues of Maskelyne between 1766 and 1805,Gould's D'Agelet for 1783, Piazzi for 1800, Auwer'sCacciatore for 1805, Bessel for 1815, a few of theearlier catalogues of Pond, Brinlkley for 1824, Besselfor 1825, Struve for 1825, Bessel for 1827, Struve for1830, Argelander for 1830, and Pulkova fqr 1845.The important catalogues of seconidary stars pub-

lished previous to 1865 are comprised in the followingtable.

[Table-omitted.]An analysis-of these catalogues reveals four impor-

tant facts:-First, that a large share of the observations relate

'to bright stars, at least to stars brighter than tht.eighth magnitude.Second, that in a large number of cases the same

star is found in different catalogues, but that no ruleis discoverable in the selection.

Third, that with the exception of the polar cata-logues of Fedorenko, Groombridge, Schwerd, andCarrington, the double-star observations of 'Struve,and the zone observations of lBessel and Argelander,the observations were not arranged with reference tothe accomplishment of a defilite object.

Fourth, that each catalogue involves a system oferrors peculiar to the observers, to the character ofthe instrument employed, anid to the system of pri-mary stars selected, but that thus far there had beenno attempt to reduce the results obtained by differ-ent observers to a homogeneous system. In esti-mating the value of these obWervations it will benecessary to refer to the researches which have beenmade subsequent to 1865.The systematic deviations of different catalogues

in right ascension inter se were nioticed at an earlydate by several astronomers; but the first attempt todetermine the law of these variations seemns to havebeen made by Safford iht a communiication to themonthly notices of the Royal astronomical society in1861 (xxi. 245), ' On the positions of the Radeliffecatalogue.' I quote the equation derived by Safford,since it appears to he the first published accounit ofa form of investigation almost exclusively followedsince that time. It is as follows:-

Diff. of R. A. (Greenw. 12 Year cat. - Rad.)-0.388. + 0.32'. sinl (a + 5 h. 32 m.). Extending thisexpression to terms of the second order, it may beput under the form, A = a constant + (m sin a + ncos a) + (i' sin 2 a + n' cos 2 a) +, etc.

Safford also seems to have been the first to noticethe conniection between the observed residuals, andthe errors in position of the primary stars employed.Hle iremarks, "In inves9g4ting the causes whichwould give rise to such systematic discrepancies, Iwas struck with the fact that the same or nearly thesame variations were apparent in the assumed places

[VOL. II., No. 29.

of the time stars for the years since 1845; that, if thecorrect positions of the time stars had been assumed,the resulting positions would have been free fromthese small errors." That the relation given by Saf-ford should have been observed at all, is the moreremarkable, since the primary stars upon which theRadcliffe positions depend are nearly the same asthose employed at Greenwich. In reality, the sys-tematic errors of both catalogues have since, beenfound. to be considerably greater than is here indi-cated, and the deviation pointed out by Safford is inthe nature of a second difference. The speaker hasshown (Proc. Amer. acad., 1874, 182) that the weightof the errors of the provisional catalogue assumed,fell between the first and the third quadrants in theRadcliffe observations for 1841-42, on account ofthe omission of certain clock stars which were usedat Greenwich.

Since the discordances which exist between twocatalogues may arise from errors in either one or inboth, it is clearly impossible either to determine thenature of the erorrs, or to assign their true cause,until a fundamnental system has been establishedwhich is free both from accidental and from periodicerrors, - from accidental errors, since a few abnormaldifferences may easily invalidate the determinationof the errors which are really periodic; from periodicerrors, because a relative system can only become-anabsolute one when one of the elements of which it iscomposed becomes absolute.We owe to the researchees of Newcomb, ,published

in 1869-70, a homogeneous system of stellar co-ordi-nates in right ascension, which are probably as nearlyabsolute in their character as it is possible to obtainfrom the data at present available. He determinedthe absolute right ascensions of thirty-two stars ofthe first, second, and third magnitudes, and comprisedbetween the limits - 300 and + 460 declination. Acomparison of the places of these stars for a givenepoch, with the same stars in any catalogue for thesa,me epoch, enables us to determine with consider-able precision the system of errors inherent in thatcatalogue. Several circumstances prevent the eieactdetermination of this relation. Among them mnay bVmentioned the fact that Newcomb's system cannotsafely be extended far beyond the limits in decli-nation of the stars comiiposing the system, that thestars are not symmetrically distributed in decliniation,and that the system of errors derived from brightstars is probably not the same as that derived fromstars of less magnitude.To a certain extent all of these objections have

been met in the later discussion by Auwers, to wlichreferenice will presently be made. The substanitialagreement of these two systems, independently deter-mined, furnishes satisfactory evidepee that we haveat last obtainied a foundation system with which it issafe to make comparisons, from which we may drawconclusions with comparative safety. When the cata-logues which were formed between 1825 and 1865are compared with Newcomb's funidamental system,through the medium of these thirty-two stars, thefollowing facts are revealed.

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a. The only catalogues in which there is freedomfromn both accidental and periodic errors are Arge-lander's Abo catalogue for 1830, and the Pulkovacatalogue for 1845. One is reminded, in this connec-nection, of the remark of Pond, that " we can hardlyobtain a better test of our power of predicting thefutture positions of stars thani by tryiing by the sameformula how accurately we can interpolate for thepast. In a variety of papers which I bave submittedto the Royal socipty, I have endeavored to show, that,with us, the experiment entirely fails."

b. During this interval the constant differences be-tween the earlier catalogues and Newcomb's systemvary between +0.176 for Pond, 1820; and - 0.19s forPond, 1830: and for later catalogues, between + 0.07Sfor Cambridge, 1860; and +.02' for Greenwiclh, 1860.

c. All the right ascensions determined at Englishobservatories, and especially those which depend uponthe positions published by the British Nautical al-manac, are too large in the region of five hours, aildtoo small in the region of eighteen hours. The gen-eral tenldency of the constant part of the deviationfrom Newcomb's system is to nieutralize the periodicerrors in the region of five hours, anid to augmentthem in the region of eighteen hours, where, in thecase of a few catalogues, the error becomes as greatas 0.10s, -a quantity which can be readily detectedfrom the observations of two or three evenings withanl indifferenit instrument, if it relates to a single star.The right ascensions determined at French observa-

tories exhibit systematic errors, which follow nearlythe same law as those which characterize Englishobservationis.

Distinctively German observations are nearly freefrom systematic errors. As far as they exist at all,their tendeency is to neutralize the errors inherent indistinctively English and French observations.

d. In the case of several catalogues, residual errorsof considerable magnitude remain after the syste-inatic errors depending upon the right ascensionshave been allowed for. These errors are fouind tobe functions of the declination of the stars observed,and without doubt have some coinnection with theformn of the pivots of the instrument with which theobservations were made. This statement holds true,especially with respect to the observations at Paris,Melbourne, and Brussels, between 1858 and 1871;and to the Washington observations between 1858and 1861.

e. The systematic errors which exist in observationsprevious to 1863 follow the same law, and have nearlythe same magnitude, as the errors of the same classwhich are inherent in the national ephenmerides ofthe country in which they were made.The British Nautical alfmanac and the Connaisance

des temps are largely responsible for the perpetuia-tion of this class of errors. For a few years beforeand after 1860, the ephemerides of the Nauticalalmanac were based upon the observations of Pond,which contain large periodic errors. It is found thatthe errors of this system lhave been tranisferred with-outt sensible diminutioni to every catalogue in whiclhthe observations depend upon Nautical almanac clock

NCE. 231

stars. At English observatories it has been tlle cus-tom to correct the positioIns of the fundainenital starsby the observations of each successive year; but thishas produced no sensible effect on the diminution ofthe periodic errors, which belong to the fundamentalsystem. The periodic errors of the Amnerican ephem-eris follow nearly the same law as the errors of theNautical almanac, but their magniitude is somewhatreduced. The error of equinox is also less.

Wolfer's Tab. reg., upon which the Berliner jahr-buch is based, has no well-defined systematic errors;and the correction for equinox is nearly the same inamount as in the American ephemeris, but with theopposite sign. The accidental errors seem to berather larger than in the system of the Americanephemeris.

f. A general estimate may be formed of the rela-tive magnitudes of the errors of secorndary cataloguesby comparing the average error for each star of theprimary catalogue. The numbers given below rep-resent the average deviation for each star, expressedin hundredths of seconds, after the various catalogueshave been reduced to a common equiinox.

Argelander.Pulkova .Greenwich .Greenwich.D'Agelet (Gould) . .

Cape of Good Hope (Henderson)Greenwich.Greenwich.ParisWashington.Strpve .Cape of Good Hope .RadClifle.Greenwich.Bessel.PondGillis.Madras (Taylor).Cape of Good Hope (Fallows)Radcliffe.Armagh.Piazzi ..Bessel's Bradley.LalandeLacaille

1830184518451860178318331850187118671846-52183018561860184018251830184018301830184518401800175518001750

Averageerror foreach star.

1.11.12.02.02.22.22.22.22.42.52.52.83.13.13.23.73.83.93.94.55.05.37.9

13.224.9

It is obvious from these relations, that previouis toabout 1825 the magniitude of the accidental errors ofobservation, combined with the errors of reduetion,prevent any definite conclusions with respect to theperiodic errors inherent in these early observations.It is probable, also, that early observations of starsof the eighth and ninth magnitudes are subject to aclass of errors peculiar to themselves, the nature ofwhich it is now well-nigh impossible to determine.The systematic errors in declination which belong

to the various secondary catalogues named are evenmore marked than those in right ascension. Theexperience of Pond in 1833 is the experience ofevery astronomer who has attempted to. compareobservations of the same star made at different times,under different circumstances, with different in-

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struments, and by different observers. He says,"Witlh all these precautions, we do not find, by com-paring the presenit observations with those of Bradleymade eighty years ago under the same roof, and com-puted by the same table of refractions, that we canobtain by interpolation any intermediate cataloguewhich shall agree with the observations within theprobable limits of error."We owe to the investigations of Auwers (Astron.

nachr., nos. 1532-15.36), the first definite system ofdeclinations which is measurably absolute in itscharacter. Yet the deviations of this system fromthat derived by the same author, but from muchadditional data in publication xiv. of the gesellsebaft,is no less than 1.2"/. The present difference outstand-ing between the Pulkova and the Greenwich sygtemiisat 100 south decliniation is 1.7"1.Within the past five years, the labors of Auwers,

of Safford, of Boss, and of Newcomb, hiave resultedin the establishment of a nmean system of declinationsfrom which accidental errors miay be considered tobe eliminated in the case of a large ntumber of stars;but the different systems still differ systematicallyinter se by quantities which are considerably greaterthan the probable error of ally single position.When the discussion of the question of a uniform

determination of all the stars in the nortlhern heavensto the ninth magniitude was taken up by the gesell-scliaft at its session in Leipzig in 1865, Argelander,who was then president of the society, appears tohave been the onily astronomer who had a clear ap-prehenision of the difficulties of the problem. liealone had detected the class of errors whose existencesubsequent investigationis have definitely established.He alone had found a well-considered plan by whichthese errors might be eliminated, as far as possible,from future observations.

Argelander, however, always claimed for Besselthe first definite proposal of the proposition uinderconsideration (see Astron. nachr., 1. 257). It was inpursuance of this plan that the zones between- 15°and + 1,5 in declinlation were observed. Thesezones were to form the ground-work of the Berlincharts; and Argelander, in the, execution of theBoinni Dux:chmusterung, simply carried-out the secondpart of Bessel's recommnendation.With the exception of the observations of Cooper

at Makree observatory, anid the charts of Chacornac,these two great works- the secoind being a con-tinuation of the first, under a better and more feasibleplan -L are the only onies in existence' which give usan,knowledge of tlle general structure of the stellarsystem.The observations of stars to the nintlh magnitude,

found in the catalogues of Bessel, Lalanide, andPiazzi, form the grounid-work of these charts. Theco-ordinates in right ascension and declination of thestars found ill these autlhorities were first reduceed tothe epoch 1800; the resultinAg right ascension beinggiven t6 seconds of time, "and the declinlation totenths of miniutes of arc. With these places as pointsof reference, all other stars were filled in, dowim tothe ninith maggifitude, by observationis with equatorial

[VOL. II., No. 29.

instruments. The work was divided into zones ofone hour each. Bremiker undertook five zones;Argelander and Schmidt, two; Wolfers, three; andHarding, two. The remaining zones were under-taken by different astronomers in widely separatedlocalities.The work seems to have been performed with

somewhat unequal thoroughness, some zones coII-taining nearly all the stars to the ninth magnitude,while in others a large number of stars having thislimit in magnitude are wanting. 0

The Durchmuisterung undertaken by Argelanderat Bonn was a far more serious and well-consideredunidertaking. This utnequalled work consists in theapproximate determinationi of the co-ordinates of324,198 stars situated between -20 anid + 900 decli-nation. It iincludes stars to the 9.5 inagnitude, theco-ordinates being given to teniths of miinutes oftime, and the declinations to tentlhs of minutes ofarc.The first d1efinite proposal of this work undertaken

by the gesellschaft, however, appears to have beenmade by Brtuhns. In the course of a report uponi theoperations of the Leipzig observatory, he stated, that,in his view, the time had come for undertaking auniform system of determiniations of the places ofstars to the ninith magnitude in the northern hemi-sphere by means of meridiain circles; but he pro-posed, at the sanme timne, that the positions of starsfainter than the ninith magniitlude should be deter-mined by means of differential observations withequatorial instruments. After explainin, certainplans anid arrangements relating particularly to hisown observatory, he introduced the following, resolu1-tioIl:-" The Astronomische gesellschaft regards it as need-

ful that all the stars to tlhe ininth mnagnitude, occurrinigin the Durchmusterung, should be observed withmeridian circles, and commissions the council toarrange for the execution of the work."

Thlis proposal occasioned a long and somnewhatanimated discussion, in which Argelanider, Hirsch,Bruhns, Fdrster, Schonfeld, and Struve took part.

Argelanider declared himself suirprised at this pro-posal, which called for the rapid realization of a planof orgatization which he had been considering foryears with the greatest care, the difficulties of whichhe had maturely considered, and the execution ofwhich still demanded the most careful deliberationand preparation. One of the necessary preliminarysteps was a plan which he had already prepared, puib-lished and presented to the society in an informalway, wlhich provided for contemporaneous and cor-respondinig observations of the brighter stars. Aspresident of the society, he felt unequal to undertak-itng the charge which the acceptance of the resolutionproposed would involve; as this proceduire seemed tohim premature without previouis preparation. Hewouild admit, however, that every call to action ofthis kind tended to stimulate enthuisiasm, aind shouldtherefore be encouraged; but he felt obliged to askthe society not to require from him the immediateexecution of the plan, but to ititrust the serious con-

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sideration of it, and the prepar-ation for it, to hiszealous friends in time council.Upon the motion of Struve, the society by a rising

vote, expressed its confidenice in the assuiranice of the

president that he would bring forward his plan at theproper time, as soon as the means for its executioncould be assured.At the meeting held at Bonn in 1867, Argelander

again brought up the suibject in a communicationwlhich appears to have been an exlhaustive discussionof the whole problem. This paper is not printed inthe proceedings of the gesellschlaft; but at its comi-

clusion a committee was appoinited to take definiiteaction with respect to the recommeindations whichl itcontained. The committee reported at tlhe same

session; and their report, which is publislhed in theplace of the paper pre-ented by Argelander, is prob-ably identical in substance with it. The platn pro-

posed and adopted was finally puiblished in the formof a programmne, in which the details of the workare arranged witlh conisiderable minuiteness. As thisprogramme lhag been widely distributed, it seems

unniecessary to give any thing more than a generalabstract of it. Since it differs ini a few minor poinitsfrom the first report of the committee at the Bonnnmeeting, the essential features of this report will begiven instead of an abstract of the programme itself.Thev are as follows: -a. The limlsits in declination of the proposed series

of observations are-26 and + 800. The first limitwas choseni oni account of the lack of suitable funda-menital stars south of the equator. It is probable,also, that Argelander had a suspicion of the fact,since proveni, that the uncertainty with respect tothe systematic errors of soutlhern stars is, of necessity,considerably greater than for niortlhern stars, and tlhaton this accounit it woul(d be better to defer this partof the work until fuirther investigations in this direc-tion could be made.

Thlie limit + 800 was chosen because the repetitionof Carrington's observationis between 810 anid 900

was considered superfluous, and Hamburg had alreadyundertaken the extension of Carrington's observa-tions from 810 to 800.

b. Within these limits, all stars in the Durchmus-terung to the ninth magnitude, and, in additioni, allstars which have been more exactly observed by La-lande, by Bessel at Koeniigsberg, and by Argelanderat Bonn, are to be observed.

c. The observations are to be differential. Theclock errors are not to be found from tlhe fundametn-tal stars usuially chosen for this purpose, amid theequator poinit corrections are not to be derived fromobservationis at upper and lower etmlminations, butthese elements are to be derived from a series of 500or 600 stars, distributted as uniiformly as possible over

the northern lheavens. The exact co-ordinates ofthese stars are to be determnined at Pulkova, thussecuritig the unity necessary in order to connect inonie systemii the observations of different zones.

d. Every star is to be observed twice. If the twoobservations differ by a quantity greater than oughtto be expected, a third observation will be necessary.

NCE. 2;3

e. In order to facilitate the work, it will be desira-ble to use oiiIoy three or four transi t thread , and( onlyone or two microscopes. In order to facilitate thereductions to apparent place, the working-list of starsslhould be comprised within inarrow limits.f. Before the commencement and after the close

of each zone, two or three fundamental stars are tobe observed upon tbe same threads and with the samemicroscopes as were used in the zone observations.When the seeing is not good, and when for any othercause it seemns desirable, one or more fundamentalstars mnay be observed in the course of the zone.The number and selection of the stars will depend.upon the character of the instrument employed. Ifit remains steady for several hours, and has nostrongly marked flexure or division errors, or if theseerrors have been sharply determined, tlle fundamenitalstars may be situated ten degrees or fifteen degreesaway from the zone limiits. However, there mustremain inany things for which no genieral rule canbe given, and which rnust be left to the judgmnenit ofthe observer, ai(led by ani accurate knowledge of hisinstruTmient.

g. With a Repsol(d or a Martin instrument, onemicroscope will be sufficient, if its position with re-spect to the whole fouir can be determnined. It willbe sufficient, if the chanige in position during theobservations can be interpolate-i to 0.2".

h. It will be desirable to divide beforehand thezones into such time intervals that the observationscan be easily made.

i. Zones exceeding onle and one-half or at the mosttwo hours are not advisable, first, because the zeropoints will be too far apart, and, secoiid, because alonger duration will involve too muclh fatigue physi-cally and mentally.At the conclusion of this report, all the astron-

omers presenit wlho were willing to take part in. thiswork were requested to conmmunicate with the couni-cil, stating the regiont of the heavens which they pre-ferred to select for observation.At this meeting, Berlin, Bonn, Helsingfors, Leip-

zig, and Maniiheim signlified their initention to sharein the work. Leiden also expressed its intenition oftaking part as soon as the work already unidertakeishould be completed.Wlhen the stars to be observed had been selected

from the Durchmusterunig, it was founld that thenumber would not vary much from 100,000, requiringrather more than 200,000 observations. Pr eparationsfor the work of observation were immediately coin-meniced; and, by the time of the next report in 1869,conisiderable progress had been madle.In the report for this year, the provisional places of

a catalogule of 539 fund(lamental stars were published.This catalogue is composed of two parts. Thie listof hauptsternie consists of 336 stars to the fourthmagnitu(le, observed at Pulkova by Wagner withthe large transit instrument, and by Gyld6n with theErtel vertical circle. The list of zusat-sternie consistsof 203 stars fainiter than the fourth magnittude. Asthe details of the work in the formation of the pIro-visional places of the stars of this list are not given

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234 SCIENCE.in the report, it is not quite clear upon what authoritythey rest. The work assigned to the Pulkova observa-tory by the zone commission was the exact determi-nation of the places of the stars of this list. Theobservations were undertaken by Gromadski withthe Repsold meridian circle. In accordance with theplan adopted, each star was observed eight times, -four times in each position of the instrument. Theobservations were differential with respect to thehauptsterne.The results were ptblished by Struve in 1876; and

the places there given were used in the first reductionof the Harvard-college observations for 1874-75, andperhaps in some other cases.About this time a change seems to have been made

in the original plan with respect to the formation ofthe final catalogue of fuindamental stars, of which Ihave been unable to find a clear account. The origi-nal intention was to make the positions depend en-tirely upon the-observations at Pulkova. The zonecommission established by the gesellschaft, bowever,committed the formatioin of this catalogue to Auwers;and it is to him that we owe the most complete andthe most perfect catalogue of fundamental stars yetpublished. The Pulkova system for 1865 was adoptedas the basis; btit, in order to obtain greater freedomfrom accidental errors for individual stars, the finalcatalogue was obtained by combining with the Put-kova series, the Greenwich observations from 1836to 1876, the Harvard-college observations for 1871-72,the Leipsic observations, in declination only, between1866 and 1870, and the Leiden observations in declina-tion between 1864 and 1870. Before this combinationwas made, however, these observati6ns were ali re-duced to the Pulkova system.The following observatories have taken part in the

zone observations:-

Limits of Limits ofObservatories. zones in Observatories. zones in

declination. declination.

Nicolajeff . -20 to + 1° Lund . . . . +35 to +40°Albany + 1 " + 5 Bonn +40 +50Leipsic . + 4 " +10 Harvard college. +50 " +55Leipsic . . +10 " +15 Helsingfors +55 "' +60Berlinl.... +15 "+25 Christiana ... +65 " +70Cambridge (Eng.) +25 " +30 Dorpat - +70 " +75Leiden . . +30 " +35 Kasan ... . +75 " +80

the zone between -20 aTid + 10 was originally un-dertaken at Palermo, that between +10 and +40 atNeuchAtel, that between +40 and +100 at Mannheim,and that between +350 and +400 at Chicago.In the latter case, the great fire at Chicago crippled

the resources of the observatory to such an extent,that Safford was comnpelled to relinquish the work,which was at that time quite far advanced.The chief items of interest ill connection with this

work are found in the followinig tabular statement:-[Table omitted.]

Attention was called, at an early date, to the Im-portance of conltinuing the survey of the niorthernheavens beyond the southern limit fixed by Argelan-

[VOL. IL., No. 29.

der. ' The preparation necessary for the execktion ofthis work consisted in the extension of the Durch-musterung to the tropic of Capricorn. This wasundertaken by Sch6nfeld at Lpipsic.In the report to the gesellschaft at the meetinig held

at Stockholm in 1877, he has given an account of thiswork, in which he stated that it was sufficiently nearcompletion to invite tlse consideration of the questionof the meridian circl* determinations of the places ofstars to the ninth magnitude. The lack of southernfundamental stars w ose positions were well deter-mined was still a hinlderance to the immediate com-mencement of the work. Relatively more stars ofthis class are required than in the inorthern observa-tions, in order to eliminate the inequalities due torefraction. Schonfeld stated, that, while the burdenof the determination of the places of these southernfundan.ental stars must rest mainly upon southernobservations, it seemed necessary to connect themwith the Pulkova system by a connecting link (mit-teiglied), through observations at sQme observatorywell situated for this purpose. At this meeting SandeBakhuysen, at Leiden, gave notice of intentionl totake part in this work. Gylddn urged the importanceof securing the co-operation of Melbourne; and Pe-ters suggested the advantage of securinig Washingtonas an additional 'mean term ' (V. J. S. 1877, p. 265).The next reference to this work is contained in

the vierteljahrsschrift for 1881, xv. p. 270. A list of303 southern stars is here given, whose exact placeswere at that time beinig determined at Leiden and atthe Cape of Good Hope. This list was selected bySchonfeld and Sande Bakhuysen, in a way to meetthe reqtuirements referred to in previous discussions.A fin-al catalogue of 83 southern fundamental stars

by Auwers appears in this number of the vierteljahrs-schrift. The places depend ujpon'the same autboritiesas for the northern stars, with the addition of the Capeof Good Hope catalogue for 1860, Williamstown, Mel-bourne for 1870, and Harvard college (Safford) for1864. For stars not observed at Pulkova, the generalcatalogue of Yarnall (1858-1861), and the Washing-ton observations, with the new meridian circle be-tween 1872 anid 1875, were employed. 'As in the caseof the northern stars, these observations are all re-duced to the Pulkova system for 1865. It is unider--derstood that the co-ordinates of the list of 303 starsare to depend uponl this extension of the generalsystem of publication xiv. to the limits required bythe southern Durchtmusterung of Schonfeld.

It would be surprising if all the conditions of suc-cess were fulfilled in the first execution of a workhaving the magnitude, and involving, the difficulties,of the scheme of observations undertaken under theauspices of the gesellschaft. The extent of the dis-cordances which are to be expected between theresults obtained by different observers can only beascertained when the observations by which the dif-ferent zones are to be connected have been reduced.Each observer extended the working-list of his ownzone 10' north and south; anid it is expected that asufficient numnber of observations of this kind hasbeen miade to determine the systematic relations

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existinig between the co-ordinates of each zone withthose of its neighbor.

It is probable, lhowever, that the experience of Gillwill be repeated on a larger scale. In 1878 lhe solicitedthe co-operation of astronomers in the determinationof the co-ordinates of twenty-eight stars, which hedesired to employ in the reduction of his heliometerobservations of the planet Mars for the purpose ofobtaining the solar parallax. The results obtainedat twelve observatories of the first class are publishedin vol. xxxix. p. 99, of the monthly notices of theRoyal astronomical society. Notwitlhstanding thefact that the final values obtained at each observa-tory depend upon several observations, the average

differenice between the least and the greatest results,obtained by different observers for each star, is 0.248.in right ascension and 2.3" in declinatioin. In fourcases the difference in right ascension exceeds 3.0,and in four cases the difference in decliination ex-

ceeds 3.0."Eveni after the results are reduced to a homogeneous

system, the following outstanding deviations from a

mean system are fouiid:-

Autbority. A a

8.

Koenigsberg . . +.005Melbournie . . +.026Pulkova. . . . +.0O5Leipsic . . . . +.049Greenwich. . +.009Berlin . +.044

As

-0.71-0.49+±0.36+0.40-0.56+0.67

Authority.

Leiden .Paris .

WashingtonHarvard college,CordobaOxford .

Aa

-.053+.055-.120-.072-.032+.076

As

-0.19+0.01+0.78+0.09-0.20+0.21

The observations of a second list of twelve stars,one-half of the iiumber beinlg comparatively bright,and the remaining half faint, showed ilo marked irn-provement, eitlher with respect to the maginitude oferrors which could be classed as accidental, or inregard to the systematic deviationis from a mean

system.This discussion revealed one source of discordance

which will doubtless affect the zone observations;viz., the differeince between right ascensionis deter-minled by the eye-and-ear method, and those deter-minied with the aid of the chronograph.The programme of the gesellschaft makes no pro-

vision for the elimuination of errors which'dependupon the magnitude of the stars observed; butspecial observations have been undertaken at severalobservatories for time purpose of defiiing the relationbetweeni tile results for stars of different magnitudes.At Hiarvard-college observatory, the direct effect of a

redutetion of the magnitude has been ascertained byreducing the aperture of the telescope by means ofdiaphragms. Beside this, the observations lhave beeiiarranged in such a mannier that an error depend-ilig upon the magnitude canl be derived from an in-vestigation of the observations upon two successivenights.At Leiden, at Albany, and perhaps at otlher

observatories, the effect of magnitude has beemi deter-mined by observations throuigh wire gauze. But

235

notwithstanding all the precautions which have beentaken in the observations, and which may be takeniin tlle reductioins, it will undoubtedly be found thatthe final results obtained will involve errors whichcannot be enitirely eliminated.

In the experience of the speaker, two other sources

of error have been detected. It has been found, thatthere is a well-defined equation between the observa-tions, which is a function of the amount, and thecharacter of the illumiiination of the field of the tel-escope. It has also been found that observationsmade under very unfavorable atmospheric conditionsdiffer systematically from those made under favorableconditions. When the seeing was noted as very bad,it is found that the observed right ascensions are

about .08 a too great, and that the observed declina-tions are about 0.8 " too great.There are doubtless other sources of error which

the discussion of the observations will bring to light.The effect of the discevery of these and other errors

will probably be to hasten the repetition of the zone

observations under a more perfect scheme, framed insuch a manner as to cover all the deficiencies whichexperience has revealed, or may yet reveal. Onewould not probably go far astray in naming the year1900 as the mean epoch of the new survey. If theobservations are again repeated in 1950, sufficientdata will then have been accumulated for at least an

approximate determination of the laws of siderialmotion.What is the present state of our knowledge upon

this subject? It can be safely said that it is verylinlited. First of all, it cannot be affirmed that thereis a sidereal system in the seinse in whiclh we speakof the solar systetn. In the case of the solar system,we have a cenitral suIn about which the planets andtheir satellites revolve in obedience to laws whichare satisfied by the hypothesis of universal gravita-tion. Do the same laws pervade the inter-stellarspaces ? Is the law of gravitation indeed universal ?What physical connection exists between the solarsystemn and the unniumbered and. inniiumerable starswhich form the galaxy of the heavenis ? Do thesestars form a systemi which has its own laws of rela-tive rest and motion ? or is the solar system a partof the stupendous whole ? Does the solar system re-

ceive its laws from the sidereal system? or has Keplerindeed pierced the deptlhs of the universe in the discov-ery of the laws which gave him immortality ? Are we

to take the alterniative stated by Ball, - either that oursidereal system is not an entirely isolated object, or

its bodies must be vastly more numerouis or nmoreulassive than even our most liberal interpretation ofobservations would seem to warrant ? Are we toconclude, for example, that stars like 1830 GI-oom-bridge and a Centauri, "after havinig travelled froman infinitely great distance oii one side of the heavens,are now passing through our system for the first andonly time, anid that after leaving our system theywill retreat again into the depths of space to a dis-tance whiclh, for any thing we can tell, may be prac-tically regarded as iinfinite " ? Can we assert withNewcomib, that in all probability the stars do not

AUGUST 24, 1883.]

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form a stable system in the sense iii which we saythat the solar system is stable, - that the stars of thissystem do not revolve around definite attractive cen-tres? Admitting that the solar system is movinigthrough space, can we at the present moment even de-termine whether that motion is rectilinear, or curved,to say nothing of the laws which govern that motion ?How much of truth is there in the conjectures ofWright, Kant, Lambert, and Mitcell, or even in themnore serious conclusions of Moedler, that the Alcyoneof the Pleiades is the central sun about which thesolar system revolves ?These are questions which, if solved at all, must be

solved by a critical study of observations of precis-ion accumulated at widely separated epochs of time.The first step in the solution has been taken in thesystematic survey of the northern heavens undertakenby the gesellsehaft, and in the survey of the south-ern heavens at Cordoba by Dr. Gould. The year1875 is the epoch about whict are grouped the datawhich, combined with similaf data for an epoch notearlier than 1950, will go far towards clearing up thedoubts wlhich now rest upon the question of the di-rection and the amount of the solar motion in space;aind it cannot be doubted that our knowledge of thelaws wlhich connect the sidereal with the solar systemwill be largely increased through this investigatioti.The basis of this knowledge must be the o6servedproper motions of a selected list of stars, so exactlydetermined that the residual mean error shall notaffect the resuilts derived; or, failing in this, of groupsof stars symmetrically distributed over the visibleheavens, sufficient in number to affect an elimina-tion of the accidental errors of observation, withoutdisturbing the equilibrium of the general system.For an investigation of this kinid, a complete sys-

tem of zone observations, at widely separated inter-vals, will afford the necessary data, if the followingcotiditions are fulfilled.

First: The proper motions must be derived by amethod which does not involve an exact knowledgeof the constants of precession. In every investiga-tion with which I am acquiainted, the derived prop-er motionis are functions of this element.

Second: The general system of proper motionsderived muist be free from systematic errors. Errorsof this class may be introduced either through theperiodic errors inherent in the system of fundamentalstars employed in the reduction of the zone observa-tions, or in a change in the constants of precession.It is in this respect that the utmost precaution willbe required. If from any cause errors of eveni smallmagnitude are introduced into the general system ofproper motions at any point, the effect of these errorsupon the values of the co-ordinates at any futureepoch will be directly proportional- to the intervalelapsed. We cani, therefore, compute the exactamount of the accumulated error for any giventime.When this test is applied to the fundamental stel-

lar systems independently determined by Auwers,Safford, Boss, and Newcombb we find the followingdeviations inter se at the end of a century,

SNCE. [VOL. II., No. 29.

Maximum Maximummeani systematic

deviation in a deviation in acentury. century.

Aa AAuwers ininus.Safford. . . -0.228- +0.21' 0.2318 1.1"t

Auwers minus Boss. . . . - +0.8 - 2.1

Auwers minu8 Newcomb. -0.09 40.8 0.06 2.2

It is the common impression, that both the directionand the amount of the motion of the solar system inspace are now well established. The conclusions 'ofStruve upon this point are stated in such explicitlanguage that it is not surprising that this impres-sion exists. He says, " The motion of the solar sys-tem in space is directed to a point in the celestialsphere situated on the right line which joins the twostars measured from ir and o Herculis. The velocityof this motion is such that the sun, with the wholecortege of bodies depending on him, advances annu-ally in the directioni indicated, through a space equalto one hundred and fifty-four inillion miles."

It must be admitted that there is a general agree-ment in the assignment by different investigators ofthe co-ordinates of the solar apex. This will be seenfrom the following tabular values.

Authorities. Right Declination.

Herschel, 1783 . . . . . . . 2570 00t +25 00'Prevost .... . . . . . 230 00 +25 00Kitugel, 1789.. . . . . . . . 260 00 +27 00Herscbel, 1805 . . . . . . . 245 52 +49 38Argelander, 1837 . . . . . . 257 49 +28 50Lundahl .2.5. . . ........252 24 +14 26Strtove .... . . . . . 261 22 +37 36Galloway .. . 260 01 +34 23M8dler ... . 261 38 +39 54

lir~~ ~ ~ ~~1256 54 +34 29Airy . . . . . . . . . . 261 29 +26 44

261 14 +3~ '55Dunkin . . . . . . . . . 26 4 +2

.~~~~~~~~~16 4+50

In estimating the value which should be attachedto these results, several considerations must be takenillto account.

(a) All of the results except those of Galloway de-pend practically upon the same authorities at oneepoch, viz., upon Brodley.

(b) The deviations inter se probably result, in alarge measure, from the systematic errors inherent Inonie or both of the fundalnental systems froln whichthe proper motions were derived. For example,Lundahl employed Pond as one of his authorities,atid it is in Pond's catalogue that the most decidedperiodic errors exist.

(c) Brot in 1812, Bessel in 1818, and Airy in 1860,reached the conclusion that the certainty of the move-ment of the solar system towards a given point in thelheavens could not be affirmed.

(d)- The problem is indirect. In the case of a mem-

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ber of the solar system, exact data will determine theexact position in orbit at a giveni time; but here we

have neither exact data, nor can we emnploy tr igono-metrical methods in the solution. We simply findthat the observed proper motionis are probably bomne-what better reconciled under the hypothesis of anl as-

sumed position of the apex of the solar motion. Themethod of inivestigationi eimiploye(d by Safford, whohas of late years given much attention to this sub-ject, consists in assutming a system of co-ordinatesfor the pole of the solar motion, from which is deter-mined the directioni each star would have if its owInproper inotions were zero. Comparinig this directionwith the observed direction as indicated by the ob-served proper Imlotion, equations of condition are

formtied from which a correction is found to the as-

sumed position of the apex, by the methods of leastsquares.

It must always be kept in minid, that the quantitieswithl which we miust deal in this investigation are

exceedinigly minute, and that the accidental errors ofobservation are at any time liable to lead to illusoryresults. The weak link in the chain of Madler'sreasoning is to be found here. I thiink we can as-

sume 0.2" as the limit of precision in the absolutedeterminationi of the co-ordinates of any star, how-

ever great the number of observatiois upon which itdepenids. Beyond this limit it is inpossible to go,

in the present date of inistrumeintal astronomy.It is safe to say, that there is Ilot a single star in

the heavens whose co-ordiniates are knowmi with cer-

tainty withini this limit. Do not misunderstand me.

Doubtless there are many stars inl whicih the errorwill at some future timiie be found to fall within thislimit. The law of probabilities requires this, if themaximum limit falls within 1". But who is preparedto select a particular star, and say that the absolutepositioIn of this star in space canniiot be more than0.2" in error ?

e. At present an arbitrary hypothesis is necessaryin the discussion of the problem. Airy assumed thatthe relative distances of the stars are proportional totheir magnitudes; and he found slightly differentresults accordiing to different modes of treatment.Safford assumed that the distanices are, at least ap-proximately, in inverse proportion to the magnitudeof the proper motioiis. The general result of his

investigations, up to this poinit, is, that there is somehope of usitng the solar motioii as a base, to advanceour knowledge of stellar distances. Later investiga-tions have been made by De Ball, but the detailshave not yet come to hanid. It is understood, how-

ever, that his results coincide in a general way withthose previously obtaiined.

It is clear from this brief review, that we have

here a field of investigation worthy of the highestpowers of the astronomer. The first step lhas beentaken in the survey of the heavens carried on under

the auspices of the gesellsehaft. It remains for the

astroilomers of the present generation to solve thedifficulties which now einviron the problem, and pre-pare the way for a more perfect scheme of observationin the next century.

NCE. 237

PAPERS READ BEFORE SECTION A.

The total solar eclipse of May 6, 1883.BY EDWARD S. HOILDEN, OF WASHBURN OBSERVA-

TORY, MADISON, WIS.THIS eclipse had the longest totality of any which

has been observed.An expedition was sent by the National academy

of sciences and the U. S. coast-survey jointly, underdirection of a commiittee from tlle former. Ex-penses were met by an appropriation of $5,000 bycongress and by the National academy of sciencesfrolm a fund left by Professor Watson. The navydepartinent also placed thie U. S. steamner Hartfordat the disposal of the academy, to tratnsport the ex-peditioni from Peru to Caroline island, whiere theeclipse was to be observed, and thence to Honiolulu.The efforts of Mr. Rockwell to provide money by

private subscriptioni for this undertaking, thioughdirectly unsuccessful, prepared the way by drawingpublic attention.

Professor Young was the chairmani of the com-mittee of tlle National academy of scienices: it wasat one tinme hoped that lhe would take clharge ofthe observing-party, but this proved imprcticable.The reports of different members of the party are tobe submitted to the Nationial academny of scienices inNovemblber. Mr. Holden has, however, permission ofthe academiiy to present an accounit of the observationbefore the American association,. It is understoodthat the presenit is not by any meanis a final report.This especially applies to the observationis of Dr.Hastings, from wlichl that gentleman concludesthat the solar corona is chiefly a phenomenon dueto the diffractioni of the solar light at the nmoon1'slinmb. The computations to demonstrate this arenot yet at hanid, but are to be completed in a few weeks.

Thie Amiiericami party consisted of Edward S.Holdent, director of Washburn observatory, Madison,Wis.; Chlarles S. Hastinigs, professor of physics in theJohns Hoplinis uniiversity, Baltimore, Md.; Charles1I. Rockwell, Tarrytown, N.Y.; E. D. Prestoii, aidU. S. coast and geodetic survey, Washiington, D.C.;Winslow Upton, U.S. signial-office, Washinlgton, D.C.;anid Enisigni S. J. Brown, U.S.N., U. S. naval observa-tory, Waslhing,ton, D.C.The original six imiembers of the party were joined,

on April 20, by four volunteer observers, all officersof the U. S. ship Hartford: these were Lieut. E. F.Qualtrough, U.S.N.; Passed assistanst-surgeon W. S.Dixon, U.S.N.; Midshipman W. S. Fletcher, U.S.N.;and Midshipman J. G. Doyle, U.S.N.On March 11 the party was strenigthened by the

joining (at Colon) of the two English gentlemen whowere seilt out by the Royal society of London tomake photographic observations of tlle eclipse, underinstructions from J. Noriman Lockyer, Esq., F.R.S.,and Capt. W. de W. Abiiey, R.E., of the science andart department of the Souith Kensingtonl museum.These were HI. A. Lawrance, Lonidon, Eng., anidC. Ray Woods, London, Eng.During the stay of the party on Caroline island

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(April 21 to May 9), ten petty officers and men of theHartford remained, and rendered very intelligentassistance.In all, the party on the island consisted of twenty-

two persons.After giving details of the proceedings of the

expeditioi, its arrival, and the preparations for theeclipse, Mr. Holden states, as to the event itself, thatthe following atmospheric conditions prevailed: Thesky proved clear at first contact, cloudy at inter-vals till near totality, clear during totality excepta slight haze in its first minutes, cloudy a fewminutes after third contact, and finally clear at fourthcontact.The meteorological observations (for which due

credit is given to the members of the party that hadthem in charge) are noteworthy. In two weeks,April 25 to May 9, twenty showers were recorded;but the rainfall in each was very small, the total inthe two weeks being about 8 inches. Half of thisfell during the only considerable disturbance of theweather, which took place May 4, when it rainedfrom midnight to 9.50 A.M.The barometer was notably uniform. Its diurnal

movements were plainly marked; the maxima beingat 9 A.M. and P.M., the minima at 3 A.M. and P.M.The indications of the thermometer were very con-stant. The daily range was 9.30, the highest reading89.30, the lowest 72.40, the daily maximum at noon,the minimum at 6 A.M. The relative humidityranged from 70 per cent at midday to 84 in earlymorning, and at no time fell below 61. The islandlies in the region of the south-east trades, but thewind (which was very steady) blew constantly be-tween north and east. The average velocity of thewind was 6.05 miles; the largest during twenty-fourhours was 212 miles, the least 59 miles; the highestvelocity, registered in a squall, was 16 miles perhour.The botanical and zo6logical observations are not

yet ready for publication. During the voyage a seriesof observations was made by Mr. Upton on southernvariable stars. Dr. Hastings and Mr. Holden,while on the island, discovered twenty-three newdouble stars, a list of which 'has appeared inSCIENCE.In preparing for the eclipse, Mr. Holden assigned

to each observer a single duty, not requiring him tomove from one instrument to another. The excel-lent photographic apparatus, prepared under the di-rection of Prof. W. Harkness of the U. S. navalobservatory, was not used: the entire field of pho-tography was left to the English party accompanyingour owIn, and to the French party under M\. Jan-ssen, who were very successful in photographing thecorona.The combination of polariscope and telescope was

used, but not with successful results, the apparatusproving unsuitable. Dr. W. S. Dixon, who attendedto a telescopic examination of the details of the innercorona, will report on the same separately, giving adrawing of the corona. With the spectroscope, thechief point of observation was as to the relative

NCE. [VOL. II., No. 29.

lengths of the line 1474 east and west of the sun.At second contact, this line was 12' longitude east and3' west. The length of 1474 east ditninished, while1474 west increased. At mid-totality these wereequal. Before the third contact, the appearanceswere reversed: 1474 west was longer and brighterthan 1474 east.At the beginning of totality, the lines 0, D3, F,

and (near G) were seen brilliaint but very short. Atmid-eclipse the spectrum was deliberately examined.On a continuous spectruim, two lines only were seen:1474 bright, and the D line dark. C, E, b, F, werecertainly wanting. Near the end of totality, C, D3,and F appeared again, very short. Five secondsafter second contact, four curved lines were seen, -C, D3, 1474, F. A light cloud passed over the sun;and oA its disappearance the spectrum showed asmall line, of about one-third the height of theothers, between 1474 and F. One hundred secondsafter second contact, three coronal rings took theplace of the lines: they were red, yellowish-green,and green', and are supposed to be C, D3, and 1474.Two hundred seconds after second contact, the redring was decidedly the brightest, and it continued toincrease in brightness during sixty seconds. Twohundred and ninety seconds after second contact,the four curved lines, C, D3, 1474, F, appeared. Thereversal of the bright lines at third contact wasobserved. The change was instantaneous, or nearlyso. The reversal of the Fraunhofer lines was notseen. The only bright line seen for the first 190seconds was 1474. A dark line was seen, which wasprobably D.Mr. Rockwell, using a Rutherford grating and

a narrow slip tangential to the limb, reportedthat 1474 K was not seen until a minute and ahalf had passed. It was followed 4' or 5' west ofthe limb, twice; and it was seen only on the west-ern side of the moon. Two green lines were alsoseen, eaeh brighter and broader than 1474, but muchshorter.

Plie credit is given by Mr. Holden to each of theobservers of the party. His own observations wereconfined to a search for the planet Vulcan, reportedto exist by Professors Watson and Swift. Mr. Hol-den's search continued durinig the whole of totality(five minutes and twenty-five seconds), with a six-inch telescope with a power of 44 and field of 57' indeclination. He saw every star on the map which hehad previously published in SCIENCE (Feb. 23, 1883),down to the sixth magnitude, inclusive, except thethirty-sixth-magnitude stars nearest to the sun; andhe saw only these stars. One of the stars of the mapwas of the same magnitude as Watson's 'Vulcan.'This was a conspicuous object. No star half sojright as this could possibly have escaped observa-tion. Mr. Holden is therefore confident that Vulcandid not exist within the limits swept over. Mr. Hol-den also deterriined the direction of the motion ofthe diffraction bands before and after totality. Thiswas an observation which he could not make suc-cessfully in Colorado in 1878, and which he believeshas not been before made.

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A new method of investigating the flexurecorrections of a meridian circle.

BY PROF. W. A. ROGERS OF CAMBRIDGE, MASS.

THE error due to refraction, the flexure of thecircle itself, and the astronomical flexure, the threebeing funietions in themselves, are most prolificerrors respectinig flexures of a meridian circle.The theory which suggested itself was arrived at

from the use on the telescope of a level of a differ-ent conistruction fronm any the author had ever seen.He had been a disbeliever inra level, but this deviceconverted him into an advocate of the level. Thelevel tube is attached to a plate, and the plateattached to the cube of the telescope. Then setthe telescope at the north point, and reverse it tothe south, reading the circle north and south. Itwould be much better were the point fixed upon aring so that it can be readily placed at any inclina-tiOIl.

Results of tests with the almacantar, intime and latitude.

BY S. C. CHANDLER, OF CAMBRIDGE, MASS.

THE instrument which has been named the 'al-macantar ' was described and figured in a paperpresented to the association at its meeting in 1880.In its general nature it is an equal altitude instru-ment. A hollow rectangular trough contaiiiing mer-cury revolves horizontally on an upright central pillar.The trough contains a float which is perfectly free toobtain equilibrium, while it is constrained to revolvewith the trough. The float carries a telescope whichtuirns on a horizontal axis, and can be clamped at anydesired altitude. When this instrument is revolvedon its vertical axis, any given point in the field ofview describes a horizontal small circle, or almacanitar,in the heavens. The transits of stars over a seriesof horizontal lines will thus afford means of deter-mining the altitude of the instrument, the error ofthe clock, the latitude or the declinations of stars,by a proper distribution of the observations inazimuth.A higher degree of accuracy is attainable by this

instrument than by a transit or a zenith telescope ofsame size. The author's comparison of results is asfollows: The probable error of a single star in deter-mining the clock error is onily ±0.05' or ±0.06'.With a transit instrument of the same size, the quan-tity is not less than ±0.08'. With the almacantarthe probable error in determining the latitude of a

sinigle star is ±0.55", including the error of the star'splace. This is about equal to the probable error of a

pair of stars by Talcott's method, with the largertelescopes of the United-States coast-survey.The instrument was a small one, -1 inches aper-

ture anid 25 inches focus. It was construieted for ex-periment only, in a provisional way, at a cost of $150.There are obvious defects in design and construction:when these are remedied, the error can be much re-duced.A series of observations with this instrument are

given by the author, for the latitude of a pier about

VCE. 239

80 feet north of the Harvard-college observatory.The value obtained by averagin, these is 0.7" lessthan given by Professor Peirce in his discussion ofthe prime vertical transit observations taken by theMessrs. Bond, and adopted as the standard value ofthe latitude of the observatory. The auithor con-cludes that Professor Peirce's value is too large byfully three-quarters of a second. By way of proofthe author gives a series of observations on the fivestars used by Professor Peirce. These are comparedwith those of Auwers and Boss, and the correction ofthe hitherto accepted value of the latitude now indi-cated by the almacantar is thereby confirmed.The clock errors of two nights selected at random,

as given by the almacanitar, were exhibited by theauthor. The results both in time and latitude wouldbe considered satisfactory with an ordinary instru-ment of two or three times the size. The almacan-tar can be made much larger than the oile undertrial, certainly of five or six inches aperture, with cor-responding increase of precision along with greateroptical power. Its mechanical construction is simple,and reduces the sources of error. Tlhus in the olderInstruments there are involved: 10. The accurateconstruction of parts, as of pivots, level, graduatedcircles. 20. Fixity of mnounting, to avoid a shiftingof the instrumental plane. 30. Rigidity of the in-struiment itself, to secure constancy of collimationand flexure. In the almacantar only the last condi-tion has to be satisfied, and it is by far the easiest ofthe three to be attained mechanically.The author regards the principle of flotation

adopted as being as delicate an indication of the di-rection of gravity as is obtained by the spirit-level.The almacantar gives promise of a niew instrument-

al resource in the higher practical astronomy. It iscompetent to deal with the most delicate problems.It will evade some of the minute sources of errorthat still cling to meridian instruments. Especially,it furnishes a method for obviating difficulties,hitherto regarded as almost insuperable, connectedwith flexure and refraction, in observations with themeridian circle.

Internal contacts in transits of the inferiorplanets.

BY J. R. EASTMAN, OF WASHINGTON, D.C.

THE author began by reviewing the different valuesobtained in observing transits of Venus, and by com-putations thereon since 1761. Eventually it becamecertain that the differences of these values dependedchiefly uipon the comnputer's interpretation of theobserver's record. The phenomenon known as the'black drop' began to be considered as an elementin the calculation. Stone regarded it as a necessaryphenomenon. He gave an explanation of its origin,and stated that the moment when a dark ligamentappears to connect the apparent limbs of the sun andVenus is the time of real internal contact. Thesecond phase, when the limbs of Venius and the sunappear in contact, Stolne says, is 'the apparent in-ternial contact.'

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In 1876 M. Andr6, the astronomer in charge of theFrench expedlition to Nowtin6a, in 1874, aniotiouceedthat " the briidge, black ligamnent, or black drop, asit is variously called, is a necessary phenomenoni unidercertain circumstances, anid not merely accidetital."He noticed, however, that " it is always possible toget rid of the ligament, and reduce the phenomenonito geometrical constants, eitlher (a) by reducing suf-ficiently the intensity of the source of liglht, or aug-inenting the absorbing power of the dark glassemployed; or (b) by covering the object glass with adark diaphragrm composed of Iritngs alternately fulland empty, all very thini, and bearing a certaini pro-portion to the focal length of the lens."These results and opinions of M. Andre were not

generally known at the time of the tranisit of Mercuryin 1878; altlhouigh his theories were cotnfirmed by hisobservations at Utah at that date, the results beingptublished by him in 1881. The black drop was seeniand recogniized in 1878 by many observers of Mer-cutry; some evidently regarding their success in find-ing it as a proof of accuracy of observatioln, othersapologizing for failing to perceive the phenomenon.The author of this paper regards it as noteworthy,

that every observer, so far as ascertainied, who got,by means of shade-glasses, the best definition of thesuni's limbs, with ani illumination less than the eyecould easily bear, did not see any trace of the blackdrop. Before seeing ally account of M. Andre's ex-periments, and having given little attentiotn to hisdeductions aninounced by Father Perry, the authorbecame independently convinced, after observationof the transit of Mercury in 1878, that the theory ofa necessary black drop was fallacious.While, in 1874, many American observers perceived

the black drop, none appear to have seen it, amongthe eight American parties organized by the transit-of-Venius commission of 1882.The paper winds up with an account of the ob-

servations of contact at the transit-of-Venus stationat Cedar Keys, Fla., last December. The observa-tion of first contact was prevented by a cloud coveringa part of the sun's disk. On the disappearance ofthe cloud, the illumnination was reduced by a slidingshade-glass, till easily endured by the eye. The defi-nition of the sun's limb was perfect. When hazeor cirri interfered, a less denisity of shade-glass waspermitted; the steadiiness anid definition of the limbremnaining, and that of Venus beinig 'all that couldbe desired,' with no modification, at the edge of thedisk, of its dense black color.Before the seconid conitact, the entire disk of Venus

was visible for several miniutes. The portion beyondthe sun's disk was bordered by a narrow line of lightmnuch less bright than the limb of the sun, and of alighter tint. About one minute before conitact, theapparent motion of the cusps of the suni, as they closedarounid the planet, noticeably increased, although themovemenit was perfectly steady. The cusps sweptaround the planet in a line of sunlight of the sametinlt as adjacent parts of the sun. This linle was asnarrow as could be seen with the power used, - 216diameters, - and was free fron tremors or pulsations.

NCE. [VOL. II., No. 29.

There was nio agitatioin in the limb of either bodynear the point of contact, nio trace of black drop,ligametnt, or banid, no change of titit or color on thelimb of Venus, and no indication .of anly clinging oftime limbs. The contact was as easily, and perhiapsas accurately, observed as the transit of a star witlhin80 of the pole, under the best comiditions. The un-certainity of noting, the time of the visible contactcould not have been greater than three-tenths of asecond. The phenomena at the thirdl contact weresimilar to those at the seconid, but, of course, in areversed order.In conclusion, the author urges hiis belief, founded

upon his own experience as well as oII study of the,work of other observers, tlhat, with a properly arrangedtelescope and stiade-glass, no observer iteed havetrouble from any phase of the 'black drop.' Toattain this end satisfactorily, the observer of conitactsmust have lno other purpose in view than such.ob-servation. The study of any branich of solar physics,or searching for somtie new thing, may, and probablywill, detract from the accuracy of his work, whichshould be confitned to obtaining the record of a gooddefinition of the sun's limb, as a reference-point inthe passage of the limb of the planet.

An improved method of producing a dark-fieldillumination of lines ruled upon glass.

BY PROF. W. A. ROGER9 OF CAMBRIDGE, MASS.

BY repeated and careful tests the author found thatby letting the light, which is held at an angle of 450,into the telescope, and then splitting the rays bymeans of two opposite mnirrors, throwing them on thehorizontal linie, ani almost perfect light is secured.Thereby it becomes practicable to see with distinct-ness stars of the smaller magnitudes upon a dark field.Other astronomers present expressed a preference

for the use of red liglht. Professor Rogers claimedthat Iiis method was better for minute observation.

'Physical phenomena on the planet Jupiter.BY. G. W. HOUGH OF CHICAGO, ILL.

TEnc rapid motion of revolution of the planet, bychanging the positioiis of the markings on the surfaceto our line of sight, makes great apparenit differencesin their shapes and sizes. This has perhaps been theoccasioII of reports of sudden anid great changes uponthe surface. The changes are not sudden, but aregradual; and many of the features are permanent.Minor changes are constantly in progress in theequatorial belts. The author recently observed thebelt drifting down toward the red spot; but althoughit partly surrounded it, they did nlot coalesce, and thespot forced a scallop into the belt, - a very curiousphenomenon. The author saw a satellite pass overthis red spot, though the satellites are not visiblewhetn on the white part of the disk. He had also hada chance to compare shadows of satellites on the diskand on the spot, and both are dark. The red spothas seemingly retrogaded during the past four years;that is to say, the rotationt of Jupiter has seemingly

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increased from 9 h. 55 rn. 33 s., to 9 ih. 55 in. 3S s.

Thie fuLture observer slhould attenid more carefully towhat he sees, and theorize afterward.

French observations onl the solar eclipse ofMay 6, 1883.

BY DR. J. JANSSEN OF PARIS, FRANCE.

A LETTER from the French astronomer Dr. Jan-ssen, who passed through this coutntry on his returinfrom an eclipse expedition, was addressed by him forthe use of tlle association to Professor Eastman, whotranslated it, and read the translation in Section A.It was thus entered as one of the papers. Dr. Jan-ssen says, -" The principal object of the observations was the

study of the dark rays in the corona. The visibilityof these rays depends more on the light-power of theinstrument than upon the perfection of the images.At first the ordinary brilliant rays which the coronapresents were reco-iized; b it what was new, andmore complete than ever expected, was that the back-ground of the coronal spectruin presented the Fraun-hofer's spectrum. All the dark rays were theoreticallyvisible. Phenomena were observed, which indicatedthat there were some portions of the corona whichreflected, much mlore abundantly than others, thelight emanating from the solar sphere: this wouldindicate the existence of cosmic imiatter circulatingaround the sun. The rings of Rispighii were notfound arranged symnetrically around the sun. Thelig,ht of the corona was strongly and radially polarized.All these things were associated with the problem ofcircumsolar cosmic inatter. The observations wentto show that no inportant intra-mercurial planetexists."

Some hitherto undeveloped properties ofsquares.

B3Y O. S. WESTCOTT OF CHICAGO, ILL.

THE paper began by ascribinig due credit to amethod for obtaining squares aiid square roots, de-scribed by Samuel Emerson in 1865. The principlesand details of that method wx ere briefly summarized.Mr. Westcott then stated the general principles of hisown method, which is very expeditious. He firstshows that the tens and units figures of all perfectsquares of numbers, from 26 to 49 inclusive, are thesame as the tens arid units figures of perfect squaresof iiumbers from 24 to 1 inclusive. A table is pre-sented as follows:

(24)2 = 576, add 100, 676 = (26)2(23)2 529, add 200, = 729 = (27)2(22)2 484, add 300, = 784 = (28)2

and so on, to(1)2 I, add 2400, = 2401 = (49)2

To determine the square of any number between25 arid 50, find the corresponding number below 25,and augment its square by the Inumber of hunidredsindicated by its remoteness from 25. Or, more con-

veniently, take the excess above 2,5 as hundreds, and

NCE. .241

augment by the square of wvhat the irumiiber lacks of50.Thus: (43)2 (43-2)) . 100+ (50 -4)2

- 180)0 + 4 = 1849Conversely: To obtain the square root of 1764.

The root is plainly between 2.5 and 50. The tens aridunilits figures in(licate S. Therefore the square rootof 1764 is 50-8 = 42.

It is further observable, that the tens and units fig-ures of perfect squares of niumbers from 51 to 99 in-clusive, are the same as the tens and units figures ofthe squares of numbers from 49 to 1 inclusive. Since4 x any nlumber of hundreds + 25, 50, or 75, gives anexact number of lhundreds, it follows that the tensand units figures of the squares of nuinbers less than25 represent all the possible combinations of figuresin those orders of units for all square numbers. Theterminations of all perfect square numibers are 22 inall: viz., 00, 01, 04, 09, 16, 21, 24, 25, 29, 36, 41, 44,49, 56, 61, 64, 69, 76, 81, 84, 89, 96.The following rule is then deduced: To square any

number froni 50 to 100, take twice the excess above50 as hunidreds, and augment by the square of whatthe number lacks of 100.Thus: (89)2 - 00 (S9-50) + (100-89)2

= 7800 + 121 - 7921Coniversely, V<24o: The root is plainly between 50and 60; the tens and units figures indicate 7 ; there-fore V3249 = 50 + 7 = 57.For greater convenience it is noted, that in such a

case as /7921 the root is 50 + 39 or 100- 11, and it iseasier to use the latter form. That is, if the rootis in the fourth quarter of the hundred, subtract thenumber indicated by the tens and units from 100, anidthe differeince is the root. Thus V82S1 =100 - 991.To square any number from 100 to 200, take four

times the excess above 100 as hundreds, and augmentby the square of what the number lacks of 200.To square any number from 125 to 250, take one-

half the excess above 125 as thousands, and augmentby what the numnber lacks of 250.By a series of steps of this character, the author

gives methods for squaring higher numbers, and con-versely for obtaining their squiare roots. A choice ofmethods is also indicated. The facility which wasobtained by such means was deftly illustrated on theblackboard by the author, who in a few seconds per-formed such exploits as raising 5 to the 16th power,and then showed in detail the processes which he hadinentally executed. The paper sets forth the reasonfor each rule, deducing it from the usual binomialtheorem, with almost obvious simplicity.The demonstrations were received by the section

witlh hearty applause. In response to an inquiry, Mr.Westcott stated, that he had been very successful inteaching this method in classes, about a tenth of hispupils becoming rapid experts in the methods ofsolution, which were especially useful in handlinigquadratic equations, aild determining at a glanicewhether a given niumber is or is not a perfect square.

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SCIENCE. [VOL. II., No. 29.

PROCEEDINGS OF SECTION B.- PHYSICS.

ADDRESS OF H. A. ROWLAND OF BAL-TIMlORE, MD., VICE-PRESIDENT OFSECTION B, AUG. 15, 1883.

A PLEA FOR PURE SCIENCE.1THE question is sometimes asked us as to the time

of year we like the best. To my mind, the spri1g isthe most delightful; for nature then recovers fromthe apathy of winter, and stirs herself to renewedlife. The leaves grow, and the buds open, with asuggestion of vigor delightful to behold; and werevel in this ever-renewed life of nature. But thiscannot always last. The leaves reach their limit;the buds open to the full, and pass away. Then webegin to ask ourselves whether all this display hasbeen in vain, or whether it has led to a bountifulharvest.So this magnificent country of ours has rivalled the

vigor of spring in its growth. Forests have beenlevelled, anld cities built, and a large and powerfulnation has been created on the face of the earth.We are proud of our advancement. We are proud ofsuch cities as this, founded in a day upon a spot overwhich, but a few years since, the red man hunted thebuffalo. But we must rememnber that this is only thesprinig of our country. Our glance must not be back-ward; for however beautiful leaves and blossoms are,and however marvellous their rapid increase, they arebut leaves and blossoms after all. Rather should welbok forward to discover what will be the outcome ofall this, and what the chance of harvest. For if wedo this in time, we may discover the worm whichthreatens the ripe fruit, or the barren spot where theharvest is withering for want of water.

I am required to address the so-called physicalsection of this association. Fain would I s-peak pleas-ant words to you on this subject; faini would I re-count to you the progress made in this subject by mycountrymen, and their noble efforts to understandthe order of the universe. But I go out to gatherthe grain ripe to the harvest, and I find only tares.Here and there a noble head of grain rises above theweeds; but so few are they, that I find the majorityof my countrymeui know them not, but think thatthey have a waving harvest, while it is qnly one ofweeds after all. American science is a thing of thefuture, and not of the present or past; and the prop-er course of one in my position is to consider whatmust be done to create a science of physics in thiscountry, rather than to call telegraphs, electric lights,and such conveniences, by the name of science. I donot wish to underrate the value of all these things:the progress of the world depends on them, and he isto be honored who cultivates them successfully. Soalso the cook who invents a new and palatable dishfor the table benefits the world to a certaiin de-

1 In using the word I science,' I refer to physical science, as Iknow nothing of natural science. Probably my remarks will,hQweverp apply to both, but I do not know.

gree; yet we do not digniify him by the name of achemist. And yet it is not an uncommon thing,especially in American newspapers, to have the, ap-phcations of science confounded with pure science;and some obscure American who steals the ideas ofsomne great mind of the past, and enriches himselfby the application of the same to domestic uses, isoften lauded above the great originator of the idea,who might have worked out hundreds of such appli-cations, had his mind possessed the necessary ele-ment of vulgarity. I have often been asked, whichwas the more important to the world, pure or appliedscience. To have the applications of a science, thescience itself must exist. Should we stop its prog-ress, anid attend only to its applications, we shouldsoon degenerate into a people like the Cbinese, whohave made no progress for generations, because theyhave been satisfied with the applications of science,and have never sought for reasons in what they havedone. The reasons constitute pure science. Theyhave known the application of gunpowder for cen-turies; and yet the reasons for its peculiar action, ifsought in the proper manner, would have developedthe science of chemistry, and even of physics, withall their numerous applications. By contenting them-selves with the fact that gunpowder will explode,and seeking no farther, they have fallen behind inthe progress of the world; and we now regard thisoldest and most ifumerous of nations as only bar-barians. And yet our own country is in this samestate. But we have done better; for we have takenthe science of the old world, and applied it to all ouruses, accepting it like the rain of heaven, withoutasking whence it came, or even acknowledging thedebt of gratitude we owe to the great and unselfishworkers who have given it to us. And, like the rainof heaven, this pure science has fallen upon ourcountry, and made it great and rich and strong.To a civilized nation of the present day, the appli-

cations of science are a necessity; and our countryhas hitherto succeeded in this line, only for the reasonthat there are certain countries in the world wherepure science has been and is cultivated, and wherethe study of nature is considered a noble pursuit.But such countries are rare, and those who wish topursue pure science in our own country must beprepared to face public opinion in a manner whichrequires much moral courage. They must be preparedto be looked down upon by every successful inventorwhose shallow mind imagines that the only pursuit ofmankind is wealth, and that he who obtains most hasbest succeeded in this world. Everybody can com-prehend a million of money; but how few can com-prehend any advance in scientific theory, especiallyin its more abstruse portions! And this, I believe,is one of the causes of the small number of personswho have ever devoted themselves to work of thehigher order in any human pursuit. Man is a grega-rious animal,,and depends very much, for his happi-ness, on the sympathy of those around him; and it is

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rare to fiid one with the courage to ptursue his own

ideals ini spite of his surroundings. In titnes past, men

were more isolate( than at present, and each came incontact with a fewer numnber of people. Hence thattime constitutes the period whlen the great sculptuires,paintings, and poens weere produced. Each main'smind was comparatively free to follow its owni ideals,and tlle results were the great and unique works ofthe ancienit masters. To-day the railroad and thetelegraph, the books and newspapers, lhave unitedeach individual man with the rest of the world: in-stead of his minid being an individual, a thing apartby itself, and unique, it hias becomne so influenced bythe outer world, an(d so dependent upoIn it, that ithas lost its originality to a great extenit. The myan

who in times past would naturally lhave been in thelowest depths of poverty, mentally and physically,to-day measures tape behind a counter, and withlordly air advises the naturally born genius how hemay best bring his outward appearance down to a

level with his own. A new idea he never had, buthe can at least cover his mental nakedness with ideasimbibed from others. So the genius of the past soon

perceives that his higher ideas are too high to beappreciated by the world: his mind is clipped downto the standard form; every natural offshoot upwardsis repressed, until the man is no higher than his fel-lows. Hence the world, through the abundance ofits intercourse, is reduced to a level. What was

formerly a grand and mnagnificent landscape, withmountains ascending above the clouds, and depthswhose gloom we cannot now appreciate, has becomeserene and peaceful. The depths have beeni filled,and the heights levelled, and the wavy harvests andsmoky factories cover the lanldscape.As far as the average man is concerned, the change

is for the better. The average life of man is farpleasanter, and his mental condition better, than be-fore. But we miss the vigor imparted by the nmoun-tains. We are tired of mediocrity, the curse of our

country. We are tired of seeing our artists reducedto hirelings, and imploring congress to protect themagainst foreign competition. We are tired of seeingour countrymen take their science from abroad, andboast that they here convert it into wealth. We are

tired of seeing our professors degrading their chairsby the pursuit of applied science instead of purescience; or sitting inactive while the whole worldis open to investigation; lingering by the waysidewhile the problem of the universe remains unsolved.We wish for something higher anid nobler in thiscountry of mediocrity, for a mountain to relieve the

landscape of its monotony. We are surrounded with

mysteries, and have been created with mincds to enjoyand reason to aid in the unfolding of such mysteries.Nature calls to us to study her, and our better feel-

ings urge us in the same direction.

For generations there have been some few studentsof science who have esteemed the study of nature the

most noble of pursuits. Some have been wealthy,and some poor; btut they have all had one thing in

common,- the love of nature and its laws. To these

few men the world owes all the progress due to ap-

NCE. 243

plied science, and vet very few ever received anypaymenit in this world for their labors.Faraday, the great discoverer of the principle on

which all maclhines far electric lihliting,, electric rail-ways, and the transmnission of power, mtust rest, dieda poor man, although otlhers an(l the whole worldhave been enriched by his discoveries. And suichmust be the fate of the followers in his footsteps forsonme time to come.BLt there will be those in the future who will study

nature from pure love, and for thenm higher prizesthan any yet obtained are waiting. We have butyet commenced our pursuit of scienice, and standupon the threshold woindering what there is within.We explaini the motion of the planet by the law ofgravitationi; but who will explain how two bodies,millions of miles apart, tend to go toward each otherwith a certain force ?We now weiglh and measure electricity and electric

currenlts with as much ease as ordinary matter, yethave we made any approach to an explanation of thephenomenon of electricity ? Lighit is an uindulatorymotion, and yet do we know what it is that undu-lates ? Heat is motion, yet do we know what it isthat moves ? Ordinary matter is a common sub-stance, and yet who shall fathom the mystery of itsinterinal constitution ?There is room for all in the work, and the race has

but commenced. The problems are not to be solvedin a moment, but need the best work of the bestminds, for an indefinite time.

Shall our country be contented to stand by, whileother countries lead in the race ? Shall we alwaysgrovel in the dust, and pick up the crumbs whichfall from the rich man's table, considerinig ourselvesricher than he because we have more crurnbs, whilewe forget that he has the cake, which is the source ofall crunmbs ? Shall we be swine, to whom the corn andhusks are of more value than the pearls? If I readaright the signs of the times, I think we shall notalways be contenlted with our inferior position.From looking down we have almost become blind,but may recover. In a new country, the necessitiesof life must be attended to first. The curse of Adamis upon us all, and we must earn our bread.But it is the mission of applied science to render

this easier for the whole world. There is a storywhich I once read, which will illustrate the true posi-tion of applied science in the world. A boy, morefond of reading than of work, was employed, in theearly days of the steam-enginie, to turn the valve atevery stroke. Necessity was the mother of inventionin his case: his reading was disturbed by his work,and he soon discovered that he mighlt become freefrom his work by so tying the valve to some mov-able portion of the engine, as to make it move itsown valve. So I consider that the true pursuit ofmankind is intellectual. The scientific study of na-ture in all its braniches, of mathematics, of mankindin its past and present, the pursuit of art, and thecultivation of all that is great and noble in the world,-these are the lighest occupation of mankind. Com-merce, the applications of science, the accumulation

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of wealth, are necessities which are a curse to thosewith high ideals, but a blessing to that portion of theworld which has neither the ability nor the taste forhiglher pursuits.As the applications of science multiply, living be-

comes easier, the wealth necessary for the purchaseof apparatus can better be obtained, and the pursuitof other things beside the necessities of life becomespossible.But the moral qualities must also be cultivated in

proportion to the wealth of the country, before muchcan be done in pure science. The successful sculptoror painter naturally attains to wealth through the le-gitimate work of his profession. The novelist, thepoet, the musician, all have wealth before them asthe end of a successful career. But the scientist andthe mathematician have no such incentive to work:they must earn their living by other pursuits, usuallyteaching, and only devote their surplus time to thetrue pursuit of their science. And frequently, by thesmall salary which they receive, by the lack of in-strumental and literary facilities, by the mentalatmosphete in which they exist, and, m1ost of all, bytheir low ideals of life, they are led to devote theirsurplus time to applied science or to other means ofincreasing their fortuiie. How shall we, then, honorthe few, the very few, who, in spite of all difficulties,have kept their eyes fixed on the goal, and have stead-ily worked for pure science, giving to the world a mostprecious donation, which has borne fruit in our

greater knowledge of the universe tndc in the applica-tions to our physical,life which have enriched thou-sands and benefited each one of us ? There aA alsothose whQ have every facility for the pursuit of science,who have an ample salary and every appliance forwork, yet who devote themselves to coamnercial work,to testifying in courts of law, and to any other work toincrease their present large income. Such men wouldbe respectable if they gave up the name of professor,and took that of consulting chemists or physicists.And such men are needed in the community. Butfor a man to occupy the professor's chair in a promi-nent college, and, by his energy and ability in thecommercial applications of his sciences st4nd beforethe local community in a prominent manner, and be-come the newspaper exponent of his science, is a dis-grace both to him and his college. It is the death-blow to science in that region. Call him by his propername, and he becomes at once a useful member of thecommunity. Put in lis place a man who shall byprecept and example cultivate his science, and howdifferent is the result! Young men, looking forwardinto the world for something to do, see before themthis high and noble life, and they, see that there issomething more honorable than the accumulation ofwealth. They are thus led to devote their lives tosimilar pursuits, and they honor the professor who hasdrawn them to something higher than they mightotherwise have aspired to reach.

I do not wish to be misunderstood in this matter.It is no disgrace to make money by an invention, or

otherwise, or to do commercial scientific work undersome circumstances. But let pure science be the aim

Y CE. [VOL. II., No. 29.

of those in the chairs of professors, and so prominentlythe aim that there can be no mistake. If our aim inlife is wealth, let us honestly engage in cominercialpursuits, and compete with others for its possession.But if we choose a life which we consider higher, letus live up to it, taking wealth or poverty as it maychance to come to us, but letting neither turn usaside from our pursuit.The work of teaching may absorb the energies of

many; and, indeed, this is the excuse given by mostfor not doing any scientific work. But there is an oldsaying, that where there is a will there is a way. Fewprofessors do as much teacihing or lecturiing as theGerman professors, who are also noted for their elab-orate papers in the scientific jouirnials. I mnyselfhave been burdened down with work, anid know whatit is; and yet I here assert that all can find time forscientific research if they desire it. But here, again,that curse of our country, mediocrity, is upon us.Our colleges and universities seldom call for first-classmen of reputation, and I have even heard the trusteeof a well-known college assert that no professor shouldengage in research because of the time wasted! I wasglad to see, soon after, by the call of a prominent scien-tist to that college, that the majority of the trusteesdid not agree with him.That teaching is important, goes without saying. A

successful teacher is to be respected; but if he doesnot lead his scholars to that which is highest, is he notblameworthy? We are, then, to look to the collegesand universities of the land for most of the work inpure science which is done. Let us therefore exam-ine these latter, and see what the prospect is.

One, whom perhaps we may here style a practicalfollower of Ruskin, has stated that while in thiscountry he was variously designated by the title ofcaptain, colonel, and professor. The story may ormay not be true, but we all know enough of the cus-toms of our countrymen not to dispute it on generalprinciples. All men are born equal: some men arecaptains, colonels, and professors, and therefore allmen are such. The logic is conclusive; and the samnekind of logic seems to have been applied to ourschools, colleges, and universities. I have before methe report of the commissioner of education for 1880.According to that report, there were 389,1 or say, inround numbers, 400 institutions, calling themselvescolleges or universities, in our country! We maywell exclaim that ours is a great country, havingmore than the whole world beside. The fact is suf-ficiemit. The whole earth would hardly support sucha inumber of first-class institutions. The curse ofmediocrity imust be upon them, to swarm in suchnumbers. They must be a cloud of mosquitoes, in-stead of eagles as they prpfess. And this becomesevident on further analysis. About one-third aspireto the name of uiniversity; and I note one called bythat name which has,two professors and 18 students,and another having three teachers and 12 students!And these instances are not uinique, for the numberof small institutions and schools which call them-selves universities is very great. It is difficult to

1 364 reported on, and 25 not reported.

I

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decide from the statistics alone the exact standing

of these institutions. The extremes are easy to main-age. Who can (loubt that an institutioni with over

800 stud(ents, anid a faculty of 70. is of a highlier grade

tlhani those above cited havingt 10 or 20 students and

two or three in the faculty? Yet this is ilot always

true; for I note one iinstitution wx ith over 500 studlenltswhich is kniowni to ine personially as of the grrade ofa higlh school. The statistics are more or less defec-tive, and it xvould muchlweaken the force of my

remtiarks if I went too much into detail. I appendthe following tables, hoxVever, of 330 so-called col-leges arid univeirsities -

218 had from 0 to 100 students.8 " 100 " 200 "

12 " " 200 " -'00' " 3())00 " 500 "

over 500

Of 822) so-called colleges an(d universities:

200 had 0 to 10 in the faculty.P': '" 10 " 20 " "17 " 20 or over " "

If the statistics wexee forthcoming,-and possiblythey mnay exist, -we might also get an idea of thestanding of these institutions and their approach to

the true university idea, by the average age of thescholars. Possibly also the ratio of number of schol-ars to teachers might be of some help. All these meth-ods give an approximatioii to the present stanidingof the institutions. But there is another method ofattacking the problem, which is very exact, but it onlygives us the )ossibilities of wvhich the institution iscapable. I refer to the wealth of the institution. Inestimating the wealtlh, I have not itncluded the valueof grounds an(I buildings, for this is of little impor-tance, either to the piesent or future staniding of theinstitution. As good work can be done in a hovel as

in a palace. I have taken the productive ftunds ofthe institution as the basis of estimate. I find: -

2:4 have below $500,000.8 " between $50(0,000 and $1,000,000.8 " over $1,000,000.

There is no fact more firnmly established, all over thexvorld, than that the higher education can never bemade to pay for itself. Usually the cost to a college,of e(ducatinig a young mlan, very much exceeds whathe pays for it, and is often tlhree or four times as

miuch. The higher the educationi, the greater thisproportion will be; and a university of the highestclass should anticipate only a small accession to itsincome from the fees of students.- Hence the testI have applied must give a true representation ofthe possibilities in every case. According to the fig-ures, only 16 colleges and universities have $500,000or over of invested funds, anid only one-half of thesehave $1,000,000 and over. Now, even the latter sum

WCE. 245

is a very small endowment for a college; and to callany institutioni a university wxhich has less than$1,000,000, is to rencder it absuird in the face of theworld. Anid yet more tlhan 100 of our institutions,maniy of themii very respectable colleges, have abusedthelcor(1 u'university' inh this manner. It is to behoped that the endowmenit of the more respectableof these inlstitutioins may be iniereased, as many oftlhemn deserve it; anti tlheir unfortu-nate appellationlhas probhld)1y been repeente(l of lonig since.

Blit what shall we think of a commiiunity that givesthe clharter of a uniiversity to an institution with atotal of $20,000 endowment, two so-called professors,an(l 1S studenits! or another witlh thlree professors,12 stuidenlts, and a total of s;27,000 ein(lowmeint, mostlyinvested in huildings! Anid yet there are very manysimilar institutions; there being 16 xvith three pro-fessors or less, and( very maniy indeed witlh only fouror five.

Suclh facts as these could only exist in a democraticcountry, where pride is tak-en in reducing every thingto a level. Anid It miay also say, that it canl onily existin the early days of suchl a demnocracy; for an intelli-gent ptublic will soon perceive thtat calling a thing bya wrong, name (loes Inot chanige its clharacter, andthat truth, above all things, slhould le tanghlt to theyouth of the natiomi.

It may be urged, that all tllese in-stitutions aredoinig good work in eduication; anid that many youngmen are thus taugiht, who coul(d not afford to go to atrue college or unliversity. Iut I do not object to theeducation, - though I have no doubt an investiga-tion would(I disclose equal absurdities here, -for it isaside fromii my object. But I do object to lowering- theideals of the youth of the couintry. Let them kniowthat they are attending a school, an-d not a university;and let them kinow that above them comes the college,and above that the university. Let thern be taughtthat they are onily half-educated, and that there arepersons in the wvorld by whose side they are butatonms. In otlher xvords, let thenm be taught the trutlh.

It may be that some small inistitutions are of higlhgrade, especially those wvhicl are new; but who candoubt that more than two-thliirds of our institutionscallingi themiiselves colleges and universities are un-worthy of the name? Each one of these institutionshas so-called professors, but it is evident that they canl)e only of the grade of teaclhers. WVhy should they niotbe so called? The position of teacher is an honoredone, but is not made more lhonorable by the assumnp-tioIi of a false title. Furthermore, the mnultiplicationof the title, and the ease xx-ith xvhiclh it can be obtained,render it scarcely worth strivilng for. When the manof eniergTy, ability, and perhaps genius is rewarded bythe samne title anid enmoluimients as the comnmonplaceman witlh the niodicum of knowledge, who takes toteaching, not because of any aptitude for his work,but possibly because he has not the energy to com-pete with his fellow-inen in buisiness, then I say oneof the inducements for first-class men to becomeprofessors is gone.When work and ability are required for the position,

and whlen the professor is expected to keep up witl

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the progress of his subject, and to do all in his powerto advance it, and when he is selected for these rea-sons, then the position will be worth working for,and the successful competitor will be honored accord-ingly. The chivalric spirit which promnpted Faradayto devote his life to the study of natuire may actuatea few noble men to give their life to scientific work;but, if we wish to cultivate this highest class of menin science, we must open a career for them worthy oftheir efforts.Jenny Lind, with her beautiful voice, would have

cultivated it to some extent in her native village;yet who would expect her to travel over the world,and give concerts for nothing ? and how would shehave been able to do so if she had wished? And sothe scientific man, whatever his natural talents, musthave instruments and a library, and a suitable andrespectable salary to live upon, before he is able to.exert himself to his full capacity. This is true ofadvance in all the higher departments of humanlearning, and yet gomething more is necessary. It isnot those in this country who receive the largestsalary, and have positions in the richest colleges, whohave advanced their subject the most: men receivingthe highest salaries, and occupying the professor'schair, are to-day doinig absolutely nothing in purescience, but are strivinig by the commercial applica-tions of their science to increase their already largesalary. Such pursuits, as I have said before, arehonorable in their proper place; but the duty of aprofessor is to advance his science, and to set an ex-ample of pure and true devotion to it which shalldemonstrate to his students and the world that thereis something high and noble worth living for. Money-changers are often respectable men, and yet theywere once severely rebuked for carrying on their tradein the court of the temple.Wealth does not constitute a university, buildings

do not: it is the men who constitute its faculty,and the students who learn from them. It is thelast and highest step which the mere student, takes.He goes forth into the world, and the height to whichhe rises has been influenced by the ideals whichhe has consciously or unconsciously imbibed in hisuniversity. If the professors under whom he hasstudied have been high in their profession, and havethemselves had high ideals; if they have consideredthe advalnce of their particular subject their highestwork in life, and are themselves hoinored for their in-tellect througlhout the world, -the student is drawntoward that which is highest, and ever after inlife has high ideals. But if the student is taughtby what are sometimes called good teachers, andteachers only, who know little m-nore than the stuident,and wlho are often surpassed and even despised byhim, no one can doubt the lowered tone of his mind.He finds that by his feeble efforts he can surpassone to whom a university has given its highest honor;and he begins to think that he himself is a borngenius, and the incentive to work is gone. He isgreat by the side of the molehill, and does not knowany mountain to compare himself with.A university should not only have great men in its

-I-NCE. [VOL. II., No. 29.

faculty, but have numerous minor professors andassistants of all kinds, and should encourage thehighest work, if for no other reason than to enicour-age the student to his highest efforts.But, assuming that the professor has high ideals,

wealth such as only a large and high university cancommand is necessary to allow him the fullest devel-opment.And this is specially so in our science of physics.

In the early days of physics and chemistry, manyiofthe fundamental experiments could be performedwith the simplest appar'atus. And so we often findthe names of Wollaston and Faraday mentioned asneeding scarcely any thing for their researches.Much can even now be done with the simplest appar-atus; and nobody, except the utterly incompetent,need stop for want of it. But the fact remains, thatone can only be free to investigate in all departmentsof chemistry and plhysics, when he not only has acomplete laboratory at his command, but a friend todraw on for the expenses of each experiment. Thatsimplest of the departments of physics, namely,astronomy, has now reached such perfection that no-body can expect to do much more in it -without aperfectly equipped observatory; and even this wouldbe useless without an income sufficient to employ acorps of%assistants to make the observations and com-putations. But even in this simplest of physicalsubjects, there is great misunderstanding. Our coun-try has very many excellent observatories: and yetlittle work is done in comparison, because no provis-ion has been made for maintaining the work of theobservatory; and the wealth which, if concentrated,might have made one effective observatory whichwould prove a benefit to astronomical science, whenscattered among a half-dozen, merely furnishes tele-scopes for the people in the surrounding region toview the moon with. And here I strike the keynoteof at least one need of our country, if she wouldstand well in science; and the following item whichI clip from a newspaper will illustrate the matter: -

" The eccentric old Canadian, Arunah Huntington,who left $200,000 to be divided among the publicschools of Vermont, has done something which willbe of little practical value to the schools. Each dis-trict will be entitled to the insignificant sum of $10,which will not advance much the cause of educa-tion."Nobody will dispute the folly of such a bequest, or

the folly of filling the country with telescopes to lookat the moon, and calliing them observatories. Howmuch better to concentrate the wealth into a fewparcels, and make first-class observatories and insti-tutions with it!

Is it possible that any of our four hundred collegesand universities have love enough of learning tounite with each other and form larger institutions?Is it possible thut any have such a love of truth thatthey are willing to be called by their right niaine?I fear not; for the spirit of expectation, which isanalogous to the spirit of gambling, is strong in theAmeiican breast, and each institution which now,except in name, slumbers in obscurity, expects in

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time to bloom out into full prosperity. Although

many of them are under religious influence, where

truth is incuilcated, and where mnen are taught to take

a low seat at the table in order that they may be hon-ored by being called up higher, and Inot dishonloredby being thrust down lower, yet these institutions

have thrust themselves into the highest seats, and

cannot probably be dislodged.But would it not be possible to so change public

opinion that no college could be founided with a less

endowment than say $1,000,000, or no university

with less than three or four times that amount?From the report of the commissioner of education,I learn that such a clhange is taking place; that the

tendency towards large institutions is increasing,and that it is principally in the west and south-westthat the multiplication of small institutions with big

names is to be feared most, and that the east is al-most ready for the great coming university.The total wealth of the four hundred colleges and

universities in 1880 was about $40,000,000 in build-ings, and $43,000,000 in productive funds. Thiswould be sufficient for one great university of $10,-000,000, four of $5,000,000, and twenty-six collegesof $2,000,000 each. But such an idea cani of course

never be carried out. Government appropriationsare out of the question, because no political trickerymust be allowed around the ideal institution.In the year 1880 the private bequests to all schools

and colleges amounted to about $5,500,000; and,although there was one bequest of $1,250,000, yet theamnount does not appear to be phenomenal. It wouldthus seem that time total amount was about five mil-lion dollars in one year, of which more than half isgiven to so-called colleges and universities. It wouldbe very difficult to regulate these bequests so thatthey might be concentrated sufficiently to produce an

immediate result. But the figures show that gener-

osity is a promiinent feature of the American people,and tllat the iieeds of the country only have to beappreciated to have the funds forthcoming. Wemust make the need of research and of puire sciencefelt in the country. We mnust live such lives of pure

devotion to our science, that all shall see that we askfor money, not that we may live in indolent ease

at the expense of charity, but that we may workfor that whiclh has advanced and will advance theworld more than any otlher subject, both intellectu-ally and physically. We must live such lives as toneutralize the influence of those wlho in high placeshave degraded their profession, or have given them-selves over to ease, and do nothing for the scienice

which they represent. Let us dp what we can withthe presenit means at our disposal. TheIe is not one

of us who is situated in the position best adapted tobring out all his powers, anid to allow hiim to do mostfor hiis science. All have their difficuilties, and I donot thlinlk that circumstances will ever radicallychange a man. If a mnan has the inistinct of research

in him, it will always show itself in some form. Butcircunmstances may direct it inito new paths, or may

foster it so that what would otherwise have died as a

bud now blossoms and ripens into the perfect fruit.

NCE. 247

Americans have shown no lack of invention insmall things; and the same spirit, when united toknowledge and love of science, becomes the spirit ofresearch. The telegraph-operator, with his limitedknowledge of electricity and its laws, naturally turnshis attention to the improvenment of the only electri-cal instrument he knows any thing about; and hisresearches would be confined to the limited sphere ofhis knowledge, and to the simple laws with which heis acquainted. But as his knowledge increases, andthe field broadens before him, as lhe studies the math-ematical theory of the subject, and the electro-mag-netic theory of light loses the dim haze due to dis-tance, and becomes his constant companion, the tel-egraph-instrument becomes to him a toy, and hiseffort to discover something new becomes researchin pure science.

It is uiseless to attempt to advance science untilone has mastered the science: he must step to thefront before his blows can tell in the strife. Further-more, I do not believe anybody can be thorough inany department of science, without wishing to ad-vance it. In the study of what is known, in thereading of the scientific journals, and the discussionstherein contained of the current scientific questions,one would obtaini an impulse to work, even though itdid not before exist. And the same spirit whichprompted him to seek what was already known,would make hiim wish to know the unknown. AndI may say that I never met a case of thorough knowl-edge in my own science, except in the case of well-known investigators. I have met men who talkedwell, and I have sometimes asked myself why theydid not do something ; but further knowledge oftheir character has shown me the superficiality oftheir knowledge. I anm no longer a believer in men

who could do sometbing if they would, or would dosomething if they had a chance. They are impostors.If the true spirit is there, it will show itself in spiteof circumstances.As I remarked before, the investigator in pure

science is usually a professor. He must teach as

well as investigate. It is a question which has beendiscussed in late years, as to whether these two func-tions would better be combined in the same individual,or separated. It seems to be the opinioni of most, thata certain amount of teaching is conducive, ratherthan otherwise, to the spirit of research. I myselfthink that this is true, and I should myself not liketo give up my daily lecture. But one must not beoverburdened. I suippose that the tirue solution, inmany cases, would be found in the mtultiplication ofassistants, not oinly for the work of teaching but ofresearch. Some men are gifted with more ideas thanthey can work ouit with their own hands, and thewoild is losing much by Inot supplying them withextra hands. Life is short: old age comes quickly,and the amount one pair of hands can do is verylimited. What sort of shop would that be, or whatsort of factory, where one man had to do all the workwith his owIn hands ? It is a fact in nature, which no

democracy can change, that men are not equal, - thatsome have brains, and some hands. And no idle

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talk about equality can ever subvert the order of theuniverse.

I know of no institution in this country where as-sistants are supplied to aid directly in research. Yetwhy should it not be so? And even the absence ofassistant professors and assistants of all kinds, to aidin teaching, is very noticeable, and must be remediedbefore we can expect much.There are many physical problems, especially those

requiring exact measurements, which cannot becarried out by one man, and can only be success-fully attacked by the most elaborate apparatus, andwith a full corps of assistants. Such are Regnault'sexperiments on the fundamental laws of gases andvapors, made thirty or forty years ago by aid from theFrench government, and which are the standards tothis day. Although these experiments were madewith a view to the practical calculation of the steam-engine, yet they were carried out in such a broadspirit that they have been of the greatest theoreticaluse. Again, what would astronomy have done with-out the endowments of observatories? By theirmeans, that science has become the most perfect ofall branches of physics, as it should be from its sim-plicity.' There is no doubt, in my mind, that similarinstitutions for other branches of physics, or, better,to include the whole of physics, would be equally suc-cessful.. A large and perfectly equipped physicallaboratory with its large revenues, its corps of pro-fessors and assistants, and its machine-shop for theconstruction of new apparatus, would be able to ad-vance our science quite as much as endowed ob-servatories have astronomy. But such a laboratoryshould not be founded rashly. The value will de-pend entirely on the physicist at its head, who has todevise the plan, and to start it into practical work-ing. Such a man will always be rare, and cannotalways be obtained. After one had been successfullystarted, others could follow; for imitation requireslittle brains.One could not be certain of getting the proper man

every time, but the means of appointment should bemost carefully studied so as to secure a good average.There can be no doubt that the appointment shouldrest with a scientific body capable of judging the high-est work of each candidate.Should any popular element enter, the person

chosen would be either of the literary-scientific order,or the dabbler on the outskirts who presents his smalldiscoveries in the most theatrical manner. What isrequired is a man of depth, who has such an insightinto physical science that he can tell when blows willbest tell for its advancement.Such a grand laboratory as I describe does not exist

in the world, at present, for the study of physics. ButIno trouble has ever been found in obtaining means toendow astronomical science. Everybody can appre-ciate, to some extent, the value of an observatory; asastronomy is the simplest of scientific subjects, andhas very quickly reached a position where elaborateinstruments and costly computations are necessary tofurther advance. The whole domain of physics is sowide that workers have hitherto found enough to do.

NCE. [vot. II., No. 29.

But it cannot always be so, and the time has evennow arrived when such a grand laboratory should befounded. Shall our country take the lead in this mat-ter, or shall we wait for foreign countries to go be-fore ? They will be built in the future, but when andhow is the quiestion.

Several institutions are now putting up laboratoriesfor physics. They are mostly for teaching, and wecan expect only a comparatively small amount ofwork from most of them. But they show progress;and, if the progress be as quick in this direction as inothers, we should be able to see a great change beforethe end of our lives.As stated before, men are influenced by the sym-

pathy of those with whom they come in contact. Itis impossible to immediately change public opinionin our favor; and, indeed, we must always seek tolead it, and not be guided by it. For pure science isthe pioneer who must not hover about cities andcivilized countries, but. must strike into unknownforests, and climb the hitherto inaccessible mountainswhich lead to and command a view of the promisedland, -the land which science promises us in thefuture; which shall not only flow with milk and honey,but shall give us a better and more glorious idea ofthis wonderful uniiverse. We must create a puiblicopinion in our favor, but it need not at first be thegeneral public. We must be contented to stand aside,and see the honors of the world for a time given toour inferiors; and must be better contented with theapproval of our own consciences, and of the very fewwho are capable of judging our work, than of thewhole world beside. Let us look to the other physi-cists, not in our own town, not in our own country,but in the whole world, for the words of praise whichare to encourage us, or the words of blame which areto stimulate us to renewed effort. For what to us isthe praise of the ignorant? Let us join together inthe bonds of our scientific societies, and encourageeach other, as we are now doing, in the pursuit ofour favorite study; knowing that the world will sometime recognize our services, and knowing, also, thatwe constitute the most important element in humanprogress.But danger is also near, even in our societies.

When the average tone of the society is low, when thehighest honors are given to the mediocre, when third-class men are held up as examples, and when triflinginventions are magnified into scientific discoveries,then the influence of such societies is prejudicial. Ayoung scientist attending the meetings of such a so-ciety soon gets perverted ideas. To his mind, a mole-hill is a mountain, and the mountain a molehill. Thesmall inventor or the local celebrity rises to a greaterheight, in his mind, than the great leader of sciencein some foreign land. He gauges himself by themolehill, and is satisfied with his stature; not knowingthat he is but an atom in comparison with the moun-tain, until, perhaps, in old age, when it is too late.But, if the size of the mountain had been seen atfirst, thee young scientist would at least have beenstimulated in his endeavor to grow.We cannot all be men of genius; but we can, at

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least, point them out to those arounid IIs. We may

not be able to benefit science much ourselves; butwe can have high ideals on the subject, and instilthem into those with whom we come in contact. Forthe good of ourselves, for the good of our country,for the good to the world, it is incumbent on us toform a true estimate of the worth and staniding ofpersons and things, and to set before our own mindsall that is great and good and noble, all that is inostimnportant for scientific advance, above the mean andlow anid uniimportaTnt.

It is very often said, that a man has a right to hisopinion. This might be true for a ian on a desertisland, wlhose error would influence onily himself.But when he openis his lips to instruct others, or even

when he signifies his opinions by his daily life, thenhe is directly responsible for all his errors of juldg-ment or fact. He has no right to think a molehill as

big as a mountain, nor to teach it, any more than helhas to thliimk the world flat, and teach that it is so.

The facts and laws of our science have not equialimportance, neithler have the men who cultivate thescience achieved equal results. One thing is greaterthan another, and we have no riglht to neglect theorder. Thus shall our minds be guided aright, andour efforts be toward that which is the highest.Then shall we see that no physicist of the first

class has ever existed in this country, that we mustlook to other countries for our leaders in that sub-ject, anid that the few excellent workers in our coun-

try must receive inany accessions from without beforethey can constitute an American science, or do theirshare in the world's work.

But let me return to the suibject of scientific socie-ties. Here American science lhas its hardest problemto contenid with. There are very miany local societiesdignlified by high-sounding names, each having itslocal celebrity, to whomn the privilege of describingsome crab with an extra claw, which he found in hismorning ramble, is inestimable. And there are some

academnies of science, situated at our seats of learningi,which are doing good work in their locality. Butdistances are so great that it is difficult to collect mentogether at any one point. The American associa-tion, which we are niow attending, is Ilot a scientificacademy, and does not profess to be more than a gath-ering of all who are interested in science, to readpapers anid enjoy social intercourse. The Nationalacademy of sciences contains eminent men from thewhole counitrv, but then it is only for the putrpose ofadvising the government freely on scientific matters.It has no building, it has no library; and it publishesnotlling except the informnation wlhich it freely givesto the government, which does nothinig for it in re-

turn. It has not had much effect directly on Amer-ican scienice; butt the liberality of the governiment inthe way of scientific expeditions, publications, etc.,is at least partly due to its iitfluence, and in thisway it has done much good. But it in no way takesthe place of tlhe great Royal society, or the great acad-emies of science at Paris, Berlin, Vienna, St. Peters-burgh, Munich, and, indeed, all the Europeatn capitalsaiid large cities. These, by their publicatioils, give

NCE. 249

to the young student, as well as the more advancedphysicist, models of all that is conisi(lered excellent;and to become a member is one of the highest honorsto which he cani aspire, while to write a memoir wlhichthe academy considers worthy to be ptublislhed in itstransactions excites each one to his highest effort.The American academy of sciences in Boston is

perlhaps our nearest representation of this class ofacademies, but its limitationi of membership to theState deprives it of its national character.But there is aniother matter which influences the

growth of our science.As it is necessary for us still to look abroad for our

highest inspiratioin in pure science, and as science isnot an affair of one town or one country, but of thewhole world, it becomes us all to read the currentjournals of science and the great transactions of for-eign societies, as well as those of our own countries.These great transactions and journials should be inthe library of every institution of learning in thecountry, where science is taught. How can teachersand professors be expected to know what has beendiscovered in the past, or is being discovered now, ifthese are not provided ? Has anv instituition a rightto mentally starve the teachiers whom it enmploys, orthe students who come to it? There can be butone answer to this; and an institutioni calling itself auniversity, and not having the currenit scientific jour-nals uipon its table or the tranisactions of societiesupon its library-shelves, is certainly not doing its bestto culltivate all that is best in this world.We call this a free country, and yet it is the only

one wlhere there is a direct tax upon the pursuit ofscience. The low state of puire science in our counI-try may possibly be attriibuted to the youth of thecountry; buit a direct tax, to prevent the growth ofour country in that subject, cannot be looked upon asotlher than a deep disgrace. I refer to the duty uponforeign books and periodicals. In our science, nobooks above elemenitary ones have ever been pub-lished, or are likely to be published, in this country;and yet every teacher in physics must lhave themn, notonly in the college library, but on his ownI shelves,and must pay the government of this country toallow him to use a portion of his smDall salary to buythat wlich is to do good to the whole country. Allfreedom of intercourse which is necessary to fosterour growing science is thus broken off; and that whichmight, in tinme, relieve our couintry of its mediocrity,is nipped in the buid by our governmenit, wlich is mostliberal when appealed to directly on scienitific sub-jects.

Onte wouild tlhink that books in foreign languagesmight be admitted free; but to please the half-dozenor so workmen who reprint German books, Inotscientific, our free intercourse with that country iscut off. Our scientific associations and societies mustmake themselves heard in this matter, and show thosein autlhority how the matter stands.In conclusion, let me say once more, that I do not

believe that our country is to remaiii long in itspresent position. The science of physics, in whoseapplications our country glories, is to arise among us,

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and make us respected by the nations of the world.Such a prophecy may seem rash with regard to a nationwhich does not yet do enough physical work to sup-port a physical journal. But we know the speed withwhich we advance in this country: we see citiesspringing up in a night, and other woniders performedat an uniprecedentgd rate. AInd now we see physicallaboratories being built, we see a great demanid forthoroughly trained physicists, who have not shirkedtheir mathematics, both as professors and in so-calledpractical life; and perhaps we have the feeling, com-mon to all true Americans, that our country is goingforward to a glorious future, when we shall lead theworld in the' strife for intellectual prizes as we nowdo in the strife for wealth.But if this is to be so, we must not aim low. The

problems of the uniiverse cannot be solved withoutlabor: they cannot be attacked without the properintellectual as well as physical tools; and no physicistneed expect to go far without his mathematics. Noone expects a horse to win in a great and long racewho lhas not been properly trained; and it would be,folly to attempt to win with one, however pure hisblood and high his pedigree, without it. The prob-lems we solve are more difficult than any race: thel)ighest intellect cannot hope to succeed without prop-er.preparation. The great prizes are reserved for thegreatest efforts of the greatest intellects, who havekept their mental eye bright and flesh hard by con-stant exercise. Apparatus can be bought with money,talents may come tous at birth;- but our mental tools,our mathematics, our experimental ability, our knowl-edge of what others have done before us, all have tobe obtained by work. The time is almost past, evenin our own country, when third-rate men can find aplace as teachers, because they are unfit for every thinBg;else. We wish to see brains and learning, combinedwith energy and immense working-power, in the pro-fessor's chair; but, above all, we wish to see that highand clhivalrous spirit which causes one to pursue hisidea in spite of all difficulties, to work at the problemsof nature with the approval of his own conscience,and niot of men before him. Let him fit himself forthe struggle with all the weapons which mathemat-ics and the experience of those gonie before himcan furnish, and let him enter the arena with thefixed and -stern purpose to conquer. Let him niotbe contented to stand back witlh the crowd of medi-ocrity, but. let him press forward for, a front place inthe strife.The whole, nniverse is before us to study. The

greatest labor of the greatest minds has only givenus a few pearls; and yet the limitless ocean, with its.hidden depths filled with diamonds and preciousstones,.is before us. The problem of the universe is,yet unsolved, and the mystery iinvolved in one sill-gle atom yet eludes us. The field of research onlyopens wider and wider -as we advance, and ourminds are lost in wonder and astonishment at thegratndeir and beauity unfolded before us. Shall wehelp in this grand work, or not? Shall our countrydo its share, or shall it still live in the almshouse ofthe world.?

NJE. [VOL. II., No. 29.

PAPERS READ BE1FORE SECTION B.

Determination of the relation between the im-perial yard and the metre of the archives.BY WILLIAM A. ROGERS OF CAMBRIDGE, MASS.THis paper was a continuation of one upon the

same subject presented at the Montreal iieeting.The mean result of the determinations up to thattime was as follows: Imperial yard + 3.37015 inches= Metre des archives.The writer stated at that time, that he should not

like to be held to a very strict account with regard tothe last decimal figure, or even the last two decimalfig'ures, on account of the difficulty of obtaining therequisite data.

Since the mbeting last year, additional data havebeen obtained. In February of the present year, acombined yard and metre was received fronm Paris.The yard was compared with the imperial yard-, in1880, by Mr. Chaney-, the warden of the imperialstandards. Durinig the interval between 1880 analFebruary of the present year, this metre has receivedrepeated comparisons with the metre of the Inter-national bureau, under the direction of Dr. Pernet.According to his report, this metre is 310 mikronstoo short at 00 centigrade; for the same temperatuire,the yard was found by Mr. Chaney to be 20.7 mikronstoo short.Comparing the metre and the yard upon this bar

with the bronze yard and metre' described at' Mont-real, and combining the results with those previouslyfound, the relation was found as follows: Imperialyard + 3.37039 inches = Metre des' archives.

The magnetophone, or the modification of themagnetic'field by the rotation of a perfo-rated metallic disk.lBY PROF. H. B. CARHART OF EVANSTON, ILL.

THE experiments of Bell, Preece, and others, onthe radiaphone, suggested the possibility of interrupt-inig, or at least periodically modifying, the lines offorce proceeding from the poles of a magnet, bymeans of a disk of sheet-iron, perforated with a seriesof equidistant holes, and rotated so that the holesshould pass directly in front of the magnetic pole.It is well known that the armature placed on thepoles of a permane4t magnet diminishes the strengthof the external field of force by furnishing superiorfacilities for the formation of polarized chains ofparticles from pole to pole. This is the case evenwhen.the armature does not touch the poles, but isin close proximity to them.

If a piece of sheet-iron be placed over the polesof a magnet without touching, and magnetic curvesbe developed on paper above the iron, they will befounld to exhibit less intense anid leis sharply definedmagnetic action than when the sheet-iron is removed.If, however, a small hole be drilled directly over eachmagnetic pole, the screeiling action of the sheet-ironis modified in much the same way as when a hole is

1 This paper will shortly be published in SCIENcE in full.

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made in a screen opaque to light; for the developedcurves show distinietly the outline of the holes. If,therefore, the sheet-ironi in the form of a circularplate, piercel with a number of holes, be rapidly ro-

tated between the poles of a magnet and smallinduction bobbins, the action of the magnet on thecore of the bobbins will be periodically modified, be-cause of the passing holes: and hence induced cur-

rents will flow through a circuit including the bobbin.A disk of sheet iron was pierced with two circles ofquarter-inch holes concentric with the disk, the num-ber of holes in the two circles being thirty-two andsixty-four respectively. On one side of the disk was

placed a horseslhoe magnet witlh its poles very near

the rows of holes; on the other side were arrangedtwo corresponding induction bobbins. The circuitwas completed through a telephone and either bobbinat pleasure. Upon rotating the disk rapidly, a clearmusical sound was produced in the telephone, thepitch rising with the rapidity of rotation. Moreover,the bobbin opposite the circle of sixty-four holesgave the octave above the other, and each gave a noteof the same pitch as was pro(luced by blowing- a

stream of air through the corresponding holes.

Magnetic survey of Missouri.

BY F. E. NIPHER OF ST. LOUIS, MO.

IN the spring of 1878 a survey of Missouri was

begun, which was expected to determine all points inregard to terrestrial magnetism: 160 points lhave beencovered. The work was undertaken under privateauspices, most of the money telndered unasked, andthe work has been carried on successfully until the

present time. The first three years were spent inmaking a preliminary survey. In the early part ofthe survey we labored under great difficulties, becauseI supposed that the linles of equal value, laid downupon the observations given in the coast - surveycharts, were substantially correct; so that time was

frequently lost in repeating values at stations leftbehind, in order to be certain that io error had beencommitted. But when we settled down to the con-

clusion that we really knew nothing about the mat-ter, we had very mucl less trouble. At first, intensitydeterminations were inade at each statioin; but in lateryears, sinice the magniets lhave proved so satisfactory,the plan was adopted of making absolute determina-tionls onily at regular intervals during the summer.

The temperature corrections for the magniet were

made twice, -once in 1878, and once two yearsago, -and they agreed very closely witlf each other.The dip circle was a large one, such as was for-

merly much used, and which was found to be an

excellent instrument, though rather clumsy to carry.The charts which have been prepared show what theresults were. In a fortner comnmunication to theassociation at Cincinnati, I suggested an explana-tion of the peculiar flexures of the isogonic lines,as being due to earth-currents wlhich seemed to

be deflected by the moist river-valleys. The mapupoIn which that hypothesis was based representedobservations taken over the entire state. By re-deter-

VCE. 251

mination we have found that those observations wereall correct; but more detailed work shows that thisexplanation is not admissible. There is Ino explana-tion of the fact that contour has any thing to do withthe deviation of the needle from the normal values.Similar flexures are also seen in the lines of equal in-clination and the lines of intensity. One and perhapstwo years will be required to accomplish the workproperly. There is nothing new in the subject, ex-cept the rather unexpected flexures which we found!in these lines. It shows very clearly that the isogonicilines which are published for the use of surveyors areof no earthly use. Work ought to be done in a de-tailed way over the whole country; and I hope weshall some time be able to combine with these deter-miniations a series of magnetic values at ten or twelvedifferent stations in the state of Missouri, and also.simnultaneous determinations of earth-currents iipoIlines making angles with each other at the differenitstations. Similar variations would probably be foundin the states of Illinois and Iowa.

In the discussion which followed, President Row-land said, that with respect to the earth-turrents, hehimself never saw any experiments which gave steadyearth-currents. Earth-currents are ustially supposed,to vary very quickly. They do not pass in, a stea(lydirection anywhere; and therefore le would inquir ewhether Professor Nipher has any reason to supposethere are such earth-currents, and, fturther, whethertllese local clhanges of these lines may not be due tohidden minies of iron, or somethliing or other, ratherthan to earth-currents.The question was also asked, whether, in comparing

earlier observations with the latert there are varia-tionIs from year to year which wotuld soon invalidalteany survey that could be mnade, antd renider it com-paratively of no val tie.

I suppose, replied Professor Nipher,. that, overrather large areas of counitry, the annual changedoes not vary very rapidly in space. Iin the westernstates, so far as I know at present, kt is pretty nearlyconstantt though I do not kniow as we have any rea-son to say that it is really constant. Replyino to thepresidenit's last quiestion, I should say that the deter-nmination to whiclh I have referred', as regards eartl-currents, was not for the puirpose of testing tlhe theorywhich I formerly had, but sitnply for the purpose ofexaminiing a cauise which certainily has somne effect.I think it is well enough known that it is a fact, aindit is well to investigate it, since we fouund so manyunexpected things. I should suppose that the ex-planation, that it is due to magnetiematter under thesurface of the earth, is the much imiore probable one,as the case stands now. As to the disposition of tlhatmagnetic matter, youi can make a great variety ou1t ofthat, anid locate your minies in varlious parts- of thestate.

Prof. A. E. Dolbear inquired whether any inves-tigations have been ma(le as to thie directioni ofearth-currenits; and whether Professor Nipher knewof any device wlliclh would enable hik to- detect the

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direction of them in any place. He had made someobservations on a line of his own, half a mile long,and had invariably found that in that line the currentis in one direction; and its electro-motive force variesfrom about one-tenth of a volt up to three volts.In regard to these lines, said President Rowland,

quick flexures of that sort must be due to local causes.They cannot be due to any thing at the centre of theearth. W`Ith respect to usinlg a line in determiningearth-currents, I think it is unsatisfactory. I do notbelieve very much' in it, myself. You can get a cur-rent in the line, but you are not certain it is in thee~rth.'A member remarked that in 1881,'in Boone County,

Missouri, he had a linie in which a continuous currentwas evinced with an electro-motive force of from twoto four volts. From 8 to 10 in the morning was themaximum, and 5 P.M. the minimulm. The line beingeast and west, the direction of the current was fromeast to west.

President Rowland said: If you put the wire on theearth's surface from onie point to another, you mere-ly determinie the difference of intensity betweeni thosepoints. It shows there is a currenit there whenl thewire is there, but not when the wire is not there.

A method of distributing weather forecasts bymeans of railways.

BY T. C. MENDENHALL OF COLUMBUS, OHIO.THis system has only been In operation, in Olio for

about a year. To distribute forecasts, we place signalsupoIn the sides of the baggage-cars, as distinct aspossible from each other, so as to be easily recog-nized at considerable distances, and also to conveyas much meaning as possible, so as to predict asimany different conditions. We adopted a combi-nation of form and color. The signals are tllreein number as to form, and two in number as tocolor. The red signals are confined to predictionsas to temperature,- rise in temperature, stationarytemperature, falling temperature. The other coloris blue, and that is cotifined to predictions inregard to the general state of the weather. Thequestion of form was a good deal considered, andthree forms were adopted. We adopted the sun,moon, and star, because everybody was familiar withthose words. We experimented with the triangle,and finally rejected it. The device for attaclhing tothe car is due to Mr. Anderson, wbo has been in theservice of the board of commissioners for the pastyear; aiid it is a really happy device. The signal ismade as large as possible, and the disk can be seen along distance.' The red sun-and blue moon meanhiglher temnperature and genieral rain. The crescentmeans lower temperature; the full disk of blue meansgeneral rain; the star represents local rainis. Withregard to the proper working of the system, thoughit has been in operation but a short time, it hasreally done good work. We receive special telegramsevery morning, and they are transmitted to the train-despatchers at fiwe o'clock. We are as yet operatingit only on one railroad. It happens, fortunately, that

EJNCE. [VOL. II., No. 29.

that road goes through an agricultural region of con-siderable importance. It is the road coinnecting thecities of Columbus and Cleveland. Two traitis startout in the morning, at the middle point betweenthose cities. The signals are put on the cars at fiveo'clock in the morning;- and as they run through themorning hours, the farmers along the line can havean opportunity of seeing them, and predicting the,weather for the day. The railway comp:uny circu-lated through the whole line little cards, havingthese signals displayed in colors, with their meaningin every combin'ation. This helps us, because it en-ables everybody to understand what is meant. Arecent communication from Gen. Hazen indicates adisposition on the part of the general government totake hold of the matter, and bring It into generaloperation as far as possible. Postal-cards have beensent to various persons along the line, with questio'nsin regard to the practical working of the system,which are answered and sent in at the end of everyweek; arid we find, that, on the average, 80 per centof the predictioils are verified.

Plan for a state weather service.BY *. E. NIPHER OF ST. LOUIS, MO.

WHILE a good many are accommodated by theweather-signals which Professor Mendenhall hasalready inaugurated, many live a distance from therailroad, anid canniot be interested in a scheme whichmakes It necessary to travel eight or ten miles to learnabout the weather, because they might be interestedin a different kind of weather by the time they gothome. Tke information might be most easily circu-lated by telegraphing from picket-stations to the west-ward. There might be a line of stations on the rail-road north and south; and stations might be foundnecessary in Nebraska, wlhlch would give immediatewarning to the central office whenever it began torain at the station; and a code might be arranged, soas to give the idea of the operator as to the probableviolence or duration of the rain. Of course it wouldbe necessary to make special study of the generallaws for the progress of summer rainis. Supposingthe information is telegraphed to the central station,the predictions can easily be made out as soon as thepicket-stations could be reached, and a clear idea ob-.tained as to the probable direction of the storm, andthe time at which it would reach the different por-tions of the state. That information could be trails-mitted by the railway companies. Finally, we shouldmake more intimate connection between these andprivate telegraph-lines which can be constructed bythe persons who are to be served with the weather-signals. This plan contemplates the erection of pri-vate telegraph-lines leading in from the country tothe sta'tions. Upon a twenty-mile line, which wouldbe a frequent length in Missouri, ten farmers willhave to pay for the erection of a couple of milesof wire, and the instruments, which can be put upfor $30 a mile. Some person could be sent from thevicinity to the director of the service, and instructionsgiven him in regard to the manner of operating the

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line and the manacgement of the batteries. The costof the line, therefore, to eaclh farmer, would be, say,

$7-, which might be distributed over ten years. Mr.

Nipher stated that in several localities the farmierswill undertake it just as sooIn as the informiiation can

be furnished them. At the stations the lines couldeasily be made to terminate in the store of some mer-

chanit, who is anxious to secure the trade of the peo-

ple oIn the line. This can be done at once in Missouri.The only thing necessary is for the state to appro-

priate a small amount of money to suipply the persons

and instruments for observations, rain-gauges, etc.The two things necessary to make it successful are

itnformation as to rainfall, and time of beginining andending of rains.

NOTES AND NEWS.-The next meeting of the American association

for the advancement of science will be held in Phila-delphia, probably during the first week in September,1884. At the session in Minneapolis last Tuesday,the following persoins were chosen as officers for the;Philadelphia meeting: Presideent: Dr. J. P. Lesley,of Philadelphia. Vice-presidents: Section A (miathe-matics and astronomy), Prof. H. T. Eddy, of Cincin-nati; B (physics), Professor John Trowbridge, ofCambridge; C (chemistry), Prof. J. W. Langley, ofAnn Arbor; D (mnechanical science), Prof. R. H.

Thurston, of Hoboken; E (geology and geography),Prof. N. H. Winchell, of Minneapolis; F (biology),Prof. E. D. Cope, of Philadelphia; G (histology andmicroscopy), Prof. T. G. Wortnley, of Philadelphia;H (anthropology), Prof. E. S. Morse, of Salemn; I

(economic science and statistics), Hon. John Eaton,of Washington. Permanent secretary: Mr. F. W.Putnam, of Cambridge. General secretary: Dr. Al-fred Springer, of Cincinnati. Assistant general sec-

retary: Prof. E. S. Holden, of Madison. Secretariesof the sections: A, Mr. G. W. Hough, of Chicago;B, Mr. N. D. C. Hodges, of Salem; C, Prof. R. B.Warder, of Cincininati; D, Prof. J. B. Webb, ofIthaca; E, Prof. E. A. Smith, of Tuscaloosa; F,Prof. C. E. Bessey, of Anmes; G, Dr. Romyn Hitch-cock, of New York; H, Mr. W. H. Holmes, of Wash-ington; I, Mr. Charles W. Smiley, of Washliigton.Treasurer: Hon. William Lilly, of Mauch Chunk.

A course of eighteen special lectuires will be givennext year to members of Johns Hopkins universityon topics relating to instruction inl the higher inisti-tutions of learning. They will be iniformal lectures.connected only by the general purpose of helpingadvanced students who are looking forward nmore or

less definitely to the work of teachers to becomefamiliar with the principles and methods followed byother persons, and with the results which have beenobtained in different types of eduicational establish-ments. The following are announced: -The present state of university and collegiate in-

struction in this country, by D. C. Gilman; Recenttobservations oni edtucational foundations in Europe,by D. C. Gilman; Natuiral and ethnic history of arith-metic, by J. J. Sylvester; The educational value of

VCE. 253

grammar, by B. L. Gildersleeve; The future sphereof classical philology, by B. L. Gildersleeve; Educa-tional value of the study of chemistry, by Ira Rem-sen; What to teach in biology, by H. Newell Martin;One lecture by H. A. Rowland; The observationalelement in mathematics, by C. S. Peirce; The a pri-ori element in physics, by C. S. Peirce; The naive ineducation, by H. Wood; Modern methods in thestudy of history, by H. B. Adams; Methods of com-parative philology as pursued to-day, by M. Bloom-field; Tihe new impetus given to the study of Latinby the application of the historical metlhod, and bythe study of inscriptions, by Minton Warren; Hy-giene in collegiate training, by E. M. Hartwell;Rhythm and eduication, by G. Stanley Hall; Tiheeducational value of specialization anid original work,by G. Stanley Hall; The uses of libraries in educa-tion, by D. C. Gilman.A course of nine lectures specially designed for

college students will also be given, as follows: -The choice of a profession, by D. C. Gilman; The

light which biograplhy throws on college life, by D. C.Gilman; Reading as an auxiliary to study, by W. HanidBrowne; The right use of translations, by C. D. Mor-ris; Historical fiction, by H. B. Adams; The Englishuniversities, by J. Rendel Harris; Recreation, by,E. M. Hartwell; Mental hygieine, by G. Stanley Hall;Science work, by Ira Remsen.- The Imperial meteorological observatory of

Japan has established a telegraphic weather-service,and at present receives reports from twenity-two well-distributed statiolns. No forecasts are yet attempted,although it is the intention to make them as soon assufficient experience will justify the step. Tri-dailymaps and bulletinis are, however, prepared. It isinteresting to note that but one telegraTn is receivedeach day from the several stations. This is sent bythe aid of a cipher, which consists of a simple com-bination of figures, not of words, as is the case in thecipher used by the U.S. signal-service. The dailydespatch is the equivalent of about eight words, anidcointains all the usuial meteorological data for each ofthe three preceding observations.- The Meteorological council publishes the results

of rainfall observations at three hunidred and thirty-six stations in Great Britain, made without interrup-tion from 1866 to 1880, under the supervision of Mr.G. J. Symons. The monthly mneans are given foreach year, for each period of five years, anid for thewhole fifteeni years. No discussion of the observa-tions is made, though it would seem that valuableconclusions couild be derived from them.-Mr. V. T. Chambers, an entomologist well

known for his studies on the Tineina, died at his resi-dence in Covington, Ky., at two o'clock on the morn-ing of Aug. 7. Durinig the afternoon of Aug. 6 hehad a stroke of paralysis, and died from its effects.He was fifty-two years old on that morning. He wasa conistant contribuitor to the Canadian ento7nolouixtand inany other entomological journals. In the Bul-letii of the U. S. geological survey there are severalpapers from his pen: viz., the Tineina of Colorado;notes oni a collection of tineid moths made in Colo-

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