NEW SERIES SUBSCRIPTION, $6.00VOL. 83, No. 2157 FRIDAY, MAY 1, 1936 SINGLE COPIES, .15

IMPORTANT new TEXTSDriver's

Tennis for TeachersNew Book--R. Norris Williams, 2nd, formerNational Singles Tennis Champion, says that"Miss Driver has worked out a method of teach-ing and counsel which is eminently sound."Mr. Williams is referring to this new book,written for-teachers and professional students.Miss Driver first sketches briefly the back-ground of tennis. She covers scoring, rules andhow to teach them, equipment, courts, termi-nology. Then she goes into the actual me-chanics of teaching and playing tennis. Thereare numerous step-by-step illustrations.12mo of 191 pages, illustrated. By HELEN IRENE DRIVER,B.A., M.S., Instructor in Charge of Women's Tennis at theUniversity of Wisconsin. Cloth, $2.50 net.

Marshall'sElementary Anatomy

New Book-Dr. Marshall has set down the lec-tures which he has been using so successfullyin his course in Anatomy at Yale. He appliesanatomy to bodily function. He includes suffi-cient of Histology to help the student under-stand anatomy. Embryology he has placed ina separate chapter to be included or omitted atthe discretion of the teacher. There are 252unusually instructive illustrations, 15 of themin colors. This text makes an excellent com-panion to Crandall's "Physiology" (opposite).12mo of 375 pages, with 252 illustrations. By CLYDE MAR-SHALL, M.D., Department of Anatomy, Yale University.Cloth, $2.50 net.

- 'g.:

Cunningham'sFamily BehaviorNew Book-Here is another new book, just offpress: It presents a subject of constantly grow-ing importance. Dr. Cunningham brings outthe direct bearing that everyday situations havein promoting or hindering the ideal state offamily affairs. She discusses social questionsof both adults and children, financial problems,community aspects, the effects of environmentand of amusements-everything that enters intothe daily routine of the average family. Men-tal hygiene is particularly stressed.12mo of 471 pages. By BESS V. CUNNINGHAM, PH.D. Cloth,$2.75 net.

Crandall'sElementary PhysiologyNew Book-This textbook sets down thosemethods of teaching which Dr. Crandall hasbeen using in his own classroom. It is freshin approach and ill the material used. Termsare defined right in the text and students -areprepared for each forward step in the study asthey progress through the book. The physio-logic functions are demonstrated by examplesfrom everyday life. There are 104 diagram-matic pictures of particular value.12mo of 325 pages, 104 illustrations. By LATHAN A. CRAN-DALL, JR., M.D., Pa.D., Associate Professor of Physiologyand Pharmacology, Northwestern University. Cloth, $2.00net.

. .. - -'.... S 8IGN AND MAL THIS ORDER FORM TODAY.

W. B. SAUNDERS COMPANY, W. W;shington Square, PhiladelphiaPlease send me the books checked (V) and charge to my account:

O Driver's Tennis for Teachers ................... $2.50 net Q] Cunningham'i 'Family Behavior ...... .......... 2.75 netO Marshall's Human Anatomy .................... $2.50 net CCkandall's Human Physiology ...... ............ 2.00 net

NAME ....ADD.,ESS . . ................. A .Entered as second-class eiatter July 18, 1923, at the Post Jfftce at Lancaster, Pa., under the Act of March 3, 1879.

2 SCIENGE-ADVERTISEMENTS

Just Published

Length of LifeA Study of the Life Table

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2 SCIENCE-ADVERTISEMENTS VOL. 83, NO. 2157

SCIENCE-ADVERTISEMENTS 3

For Plus Value

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VOL. 83, NO. 2157

MAY 1, 1936 SCIENCE-ADVERTISEMENTS 5

IT'S TIME FOR ACTION-OR ELSE!Ruthless Depression has had many a school laboratory "down for the count" of six longyears . . . sluggish years in which the devitalizing forces of dwindled equipment havebeen actively at work retarding the rightful progress of students and instructors alike.This irreparable damage is enough to cause serious alarm and prod into action thosewho are at the helm of this vital branch of learning. Whether or not your laboratoryfelt the full force of depression's blow, you cannot afford to overlook the reviving andprogressive merits of new, up-to-date apparatus and supplies. The depression-unwel-come as it has been-has taught shrewd sdience instructors that the suppression of lab-oratory wants and needs is not a virtuous conservation of funds. For, these things rep-resent far greater security to the instructor,to the student and to the school than theirequal in cash in the bank. Accordingly, youowe it to yourself to reach for your MilvayCatalog. It gives you compactly and sys-tematically summarized, the complete lineof Milvay values and you can depend onit as your sole source of supply.

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VOL. 83, NO. 2157

SCIENCE-ADVERTISEMENTS

WEBER ELECTRIC VACUUM OVENSNEW MODEL WITH DOOR CLAMP

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SCIENCE-ADVERTISEMENTS

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-~~~. I*

VOL. 83, NO. 2157

VOL. 83, No. 2157

tool self-sharpening. This method of applying hard-facing material to but one face is said3 to have workedvery well with other digging parts, such as powershovel teeth and plowshares.We decided upon simulated rather than actual field

experiments in order that we might perform as nearlyas possible exactly the same routine with the twopicks, since it can readily be appreciated that manualdigging might easily have resulted in serious errorsin a comparative study of the wearing qualities of amodified and an unmodified Brown pick.A hole was bored through an extension of each pick

handle 36 inches from the pick end and a round ironrod of slightly smaller diameter passed through theholes and securely fastened to supports in such man-ner that the picks could only move up and down. Thepicks could then be lifted and allowed to fall freelythrough equal anid controlled distances upon selectedobjects. The lifting and release of the picks wassecured by the revolution of two eccentrics of thesame size fastened to an axle which was geared to aone-fourth horsepower motor. The end of the pickhandle farthest removed from the head was depressedas the eccentric was revolved by the motor and thepick elevated, then suddenly released as the eccentriccontinued its revolution, and as soon as one pick wasreleased for its downward stroke the other was quicklyelevated. Speed-reducing gears were introduced be-tween the motor and the revolving shaft, thereby regu-lating the number of strokes delivered by each pickto twenty-six per minute. The length of arc throughwhich the pick points rose and fell was approximatelyseven inches. A counter was attached to the shaftand each complete revolution of the shaft, and there-fore the number of strokes delivered by each pick wasautomatically recorded.4A total of eight thousand strokes were delivered by

each end of each pick, distributed as follows: Alberene(a soft stone)-1,000 strokes; old brick-1,000; sand-stone-1,000; concrete I (interior of a broken block)-1,000; concrete II (surface of U. S. Highway I)-3,000; polished, fine-grained white marble-1,000.The digging operation was interrupted after each fivehundred strokes and the specimen turned so that eachpick now dug where the other had been digging.

Neither pick showed much sign of wear after impactupon alberene and old brick, but beginning with sand-stone a decided difference in the two picks was ob-served. The pointed end of the original Brown pickquickly became blunted and rounded off so that its

3Oxy-Acetylene Tips, 6: 58, 1928.4 The general idea of the testing machine was described

to Mr. J. M. Holeman and Mr. J. B. Weems, Jr., studentsat Randolph-Macon College. The writer expresses hisappreciation of the time and efforts expended by them indesigning and constructing it.

effectiveness was materially lost and could only berestored by resharpening. At the same time andunder the same working conditions the hard-facedpick became self-sharpening, the alloy showed no evi-dence of wearing and only the steel undercoat woreaway. The results were even more noticeable at thespatula end. Since this is relatively thin for somedistance, the alloy applied to the outer face composeda relatively larger cross-section than at the pointedend. Even very slight wearing away of the steel lefta wear-resisting knife edge which was effective indigging very hard materials, such as marble and con-crete, although a slight loss of alloy by chipping re-sulted. The unmodified steel spatula was badlybruised and roughened by sandstone, concrete andmarble. Practically no effective digging was done onthe two latter materials by the original steel pick.

It is the conclusion of the writer that the usefulnessand effective life of this valuable tool can be mate-rially increased by the application of Haynes Stellite2or some similar hard-facing alloy. These improvedpicks are not on the market. Perhaps it should benoted that the application of this alloy requires theservices of a good welding operator. In addition, thealloy is too hard for machining and must be finishedby grinding.

I. A. UPDIKERANDOLPH-MACON COLLEGEASHLAND, VA.

BOOKS RECEIVEDActualit6s Scientifiques et Industrielles. No. I, Thixo-

tropy, by H. FREUNDLICH. Pp. 50. No. II, Activit6et Interaction lonique, by M. QUINTIN. Pp. 33. No.III, Recherches Analytiques sur LA'Arginine et L'His-tidine, by JACQUES BusSIT. Pp. 100. No. VI, L 'Ac-tion Chimique des Rayons Alpha en Phase Gazeuse, byW. MUND. Pp. 51. No. VII, Les Thermostats pourles Temp&ratures Moyennes, by ANDRa LALANDF Pp.54. No. X, Contribution d L 'Atude de la Constitutionde L 'Amidon, by R. SUTRA. Pp. 62. Hermann & Cie,Paris.

Anales de la Universidad Central. Tomo LVI, No. 295,March, 1936. Pp. 328. Publicacion Trimestral. Uni-versidad Central del Ecuador, Quito.

Collected Scientiflc Papers of Sir William Bate Hardy.Pp. x+922. 15 plates. Cambridge University Press,Macmillan. $18.00.

CRUM, Roy W., Editor. Highway Research Board; Pro-ceedings of the Fifteenth Annual Meeting, 1935. Pp.394. Illustrated. National Research Council, Wash-ington.

MAETERLINCK, MAURICE. Pigeons and Spiders. Trans-lated by BERNARD MIALL. Pp. 128. Norton. $1.75.

READ, BERNARD E. Chinese Medicinal Plants from the PenTs 'ao Kang Mu. Third edition. Pp. xvi + 389. Pub-lisher, Peking Natural History Bulletin, 1936. SalesAgent, The French Bookstore, Peiping.

ToBiAS, J. CARROLL. The Student 's Manual of Micro-scopic Technique. Pp. xvii + 210. 79 figures. Ameri-can Photographic Publishing Co., Boston. $2.50.

WADDINGION, C. H. How Animals Develop. (A shortoutline of embryology.) Pp. 128. 30 figures. Norton.$2.00.

422 SCIENCE

MAY 1, 1936 SCIENCE-ADVERTISEMENTS 9

ANNOUNCINGthe first volume in the

McGRAW-HILL SERIES IN GEOGRAPHY

V. C. FINCH, Consulting Editor

ELEMENTS OF GEOGRAPHYBy V. C. FINCH

Professor of Geography, University of Wisconsin

and GLENN T. TREWARTHAAssociate Professor of Geography, University of Wisconsin

768 pages, 6 x 9, fully illustrated, with envelope of nine folding work maps. $4.00

TlHE chief merit of this important new book for beginning courses lies in the choice of material,in the structure of its organization, and in the manner of its presentation. The selection of

material has been made with a single objective: to describe and depict the major componentelements of geographic landscape, and to enable the student to interpret the significance of theirareal association. The structure of the book's organization includes (a) three opening chapterswhich provide a degree of orientation in the field of geography together with certain basic facts andgeographical tools, and (b) three principal parts: the elements of natural earth, the elements ofmaterial culture, and the geographic realms. An outstanding feature of the book is the wealth ofexcellent illustrations. The plates which accompany the book have been prepared in blank forstudent drawing and coloring.

About the Series

The McGraw-Hill Series in Geography is intended to contribute to American college education byproviding text and reference volumes that will keep pace with factual and philosophical develop-ments in the field of natural environment, the regional and distributional aspects of human geo-graphy and in geographical methods and techniques. It is hoped also that the Series may have animportant part in the advancement of the growing science of regions, the evaluation of their con-tents and the planning of their administration.

Send for a copy on approval

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MAY I, 1936 SCIENCE-ADVERTISEMENTS 9

330 West 42nd Street, New York

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ELEMENTS OF PSYCHOLOGYBY

KNIGHT DUNLAPProfessor of Psychology in the University of Cali-fornia at Los Angeles; until January, 1936, Professor-of Experimental Psychology in the Johns Hopkins

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'MAY I) 1936 SCIENCE-ADVERTISEMENTS 11