Gage, Alfred P. (Alfred Payson), 1836-1903, Fessenden, C · Toronto : W.J. Gage · leaf 316
the original iswi-itten in dark letters on a light ground, the message is receivedin light letters on a dark ground. Pen-and-ink sketches of pho-tographs and other pictures may be transmitted in the sameway. The pens are not, of course, held and guided by humanhands, but by complex machinery. The… … § 244. The electric fire-alarm. — This is a modificationof the electro-magnetic telegraph. Figure 199 will serve toillustrate the general plan of the American system, invented by jf. 294 ELiECfRICIfY AN^D MAGitEflSM. Prof. M. G. Farmer, and by him first introduced into Boston inthe year 1852. From…
Physics
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