Theory and practice of the electric telegraph; a manual for operators and students (1875)
Churchill, Charles Henry, d. 1904. [from old catalog] · Oberlin, Ohio, Sherman & bros. · leaf 73
ester. into the lower plate and thus to the ground, while the voltaic current will not go through the silk. 19. Describe Bradleys arrester? Bradley substitutes air for the varnished silk and has sharppoints attached to each plate reaching nearly over to theother plate. This is a very effective… … THE ELECTRIC TELEGRAPH. 53 way stations to open and close the circuit of a second batterywhich continues the message to a third and so on withoutrewriting. The apparatus for this is called a repeater. It isnearly the same in form as a relay or sounder. 21. How far may messages be sent by this…
Telegraph
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