Flame, electricity and the camera; man's progress from the first kindling of fire to the wireless telegraph and the photography of color (1900)
Iles, George, 1852-1942 · New York, Doubleday & McClure co. · leaf 260
isjoined to the metallic cir-cuit of the voltaic cellM. In this circuit orchain, the coherer, when unexcited, forms a link whichobstructs the flow of a current eager to leap across. Theinstant that an electric wave from the sending-station im-pinges upon the coherer it becomes conductive; the… … 1- ■Fig. 72.Marconi telegraph apparatus. 222 WIRELESS TELEGRAPHY An electric impulse, almost too attenuated for computa-tion, is here able to effect such a change in a pinch of dustthat it becomes a free avenue instead of a barricade. Throughthat avenue a powerful blow from a local store of…
Fire · Electricity · Color photography
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