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 248
Plate IV. From photograph by London Stereoscopic Co.LORD KELVIN. CHAPTER XV MULTIPLEX TELEGRAPHY AS long as rays of light were the sole resource of theJL\^ signaller, all that he did, or could do, was to send asingle message at a time. When telegraphy passed fromlight to electricity as its agent,… … Fig. 64.Delany perforated message, telegraphy. harmonic method of making a wire carry at the samemoment several messages unconfused. We noted alsoone of the inventions of Mr. P. B. Delany for increasingthe capacity of a wire by sending messages at a rate pos- 207 208 MULTIPLEX TELEGRAPHY sible only…
Technology · Fire · Electricity · Photography
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