Meadowcroft, Wm. H. (William Henry), b. 1853 · New York & London, Harper & brothers · leaf 41
sending a telegram is simpleenough. The apparatus that is used in send-ing a telegram is as follows: The Battery.The Wire. The Telegraph Key.The Sounder. The different kinds of electric batterieswill be mentioned afterward, so we will notstop now to describe them, but simply statethat a battery is… … Fig. 6 This instrument is usually made of brass,except that upon the handle there is the littleknob which is of hard rubber. The handle,or lever, moves down when this knob ispressed, and a little spring beneath pushesit up again when let go. You will see asecond smaller knob, the use of which we…
Electricity
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![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer02inte-116-27.webp)
