Radium, and other radio-active substances : polonium, actinium, and thorium. With a consideration of phosphorescent and fluorescent substances, the properties and applications of selenium, and the treatment of disease by the ultra-violet light / by William J. Hammer.

  • Hammer, William Joseph, 1858-1934.
Date:
1903
Catalogue details

Licence: In copyright

Credit: Radium, and other radio-active substances : polonium, actinium, and thorium. With a consideration of phosphorescent and fluorescent substances, the properties and applications of selenium, and the treatment of disease by the ultra-violet light / by William J. Hammer. Source: Wellcome Collection.

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    I shall hope to show you in actual operation, as I have had them working most successfully in my laboratory; and you will see that by merely passing my hand before the selenium cell, I can start and stop the motor, turn the light on and off, and ring the bell and blow the horn, or I can fire this cannon, start my phono- graph talking, etc. I am indebted to the courtesy of the Marconi Co. for the large relay used in certain of these experiments. I have here also a 3 h.p. motor, driving a H k.w. generator and Fig. 20.—Manometric Acetylene Flame Transmitter with Selenium Cell, etc.—(a battery of about 24 volts employed). supplying these lamps which have been courteously supplied by the General Electric Co.; and by means of this selenium cell, relay, battery and a motor starter, for which I am indebted to the Cutler-Hammer Co., I hope to be enabled to start and stop the motor by merely passing my hand before the selenium cell. In Fig. 22 is shown a portion of the stage setting at the