Boys' own book : a complete encyclopedia of athletic, scientific, outdoor, and indoor sports (1881)
Clarke, William, 1800-1838 · New York : J. Miller, Publisher · leaf 488
n appropriate surface so as to change its apparentdirection, by producing an artificial echo. He then showedthem the pipe which was concealed in one of the legs of theframe, and explained in what manner the voice of Tom Plank,who had been stationed in an adjoining room, was conveyedto the mouth of… … J & represent two of the legs of the frame, one of which, aswell as half the rail, is made into a tube, the end of whichopens immediately opposite to the center of the trumpet.This hole is very small, and concealed by moldings; theother end communicates by a tin pipe f p, which passes in…
Amusements · Games · Sports
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