Last month, we showed how young men a hundred years ago could set up a telegraph system to communicate with a friend down the street, using, of course, Eveready batteries. But what if the friend lived across the street?  According to this ad in the November 1924 issue of Boys’ Life, running a wire across the street might not be possible, since many towns forbade it.  But there was still a solution in the form of this lamp signaling outfit.  With three Eveready dry cells, and a four-volt Eveready automotive lamp, your friend across the street could easily copy your code visually.

Of course, before taking the key, it was best to put on a tie.

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