John Keel - Moon Craters - Or Secret UFO Bases

The Influence of the Blue Ray of the sunlight and of the Blue Colour of the Sky by Gen A J Pleasonton, 1877

Harmonies of Tones and Colours Developed by Evolution by F J Hughes, 1883

Atoms, Molecules, And Ether Waves - John Tyndall

Magnetic Rotations - E L VOICE

The Cause of Evident Magnetism in Iron - Professor D E Hughes