Uncompounded thallium is used in low-melting glasses, photoelectric cells, switches, mercury alloys for low-range glass thermometers, and thallium salts.
22.
Two German chemists, Robert Bunsen and Gustav Kirchhoff, discovered caesium in 1860 by the newly developed method of photoelectric cells.
23.
Both systems used photoelectric cells made by Lloyd Preston Garner; a researcher at the University of Illinois at Urbana Champaign.
24.
The images were of low definition and mechanically scanned, using three complete systems of photoelectric cells, amplifers and glow tubes.
25.
The light reflected from the subject was picked up by banks of photoelectric cells and amplified to become the video signal.
26.
:: : Some lights are on timers and others are on photoelectric cells that turn them on when it gets dark.
27.
Kunz also collaborated with electrical engineering professor Joseph TykociDski-Tykociner to use a photoelectric cell to photograph sound and reproduce it electronically.
28.
The reflected light would be picked up by a photoelectric cell whose electrical output would vary with the intensity of the light.
29.
Kunz s photoelectric cells were many times more sensitive than what was available commercially and therefore able to detect faint star light.
30.
The early photoelectric cells were not very sensitive, so three or four would be used with the subject in a darkened booth.
