New York [etc.] Simmons-Boardman Pub. Co. [etc.] · leaf 294
nary India rubber gastube about 3 ft. in length. The lengtli, may, how-ever, be varied to suit the nature of the investiga-tion. No ear piece or bell is needed on the tube.One end is applied to the ear of the observer, whilethe other is moved about in order to locate the noise.It is said that this…
Railroads · Railroad cars
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