Rensselaer Republican, Volume 20, Number 17, Rensselaer, Jasper County, 29 December 1887 — DRAWBA UGH’S LATEST. [ARTICLE]

DRAWBA UGH’S LATEST.

An Invention That Discoveiw the Movement of Bodies Miles Away. Additional details of the invention of Daniel Drawbaugh, of Harrisburg, Pa., by which the presence of large bodies of men on laud or of ships on the ocean can be detected, have been made public by the inventor. The instruments consist of what Drawbaugh calls a microphone itnd a registering dial. The microphone, an extremely sensitive combination of wire, is placed in a hollow iron, tube, hermetically sealed. The micropnone, when used on land, is attached to an iron screw with a very wide thread by means of which it is sunk firmly into the earth. An insulated wire, which may be buried or run ovet tree topiq connects with a galvanic battery and the registering dial, which may be placed miles away. The registering dial is surmounted by a needle which works from a zero point. Underneath the dial in a small, circular brass box is another needle in the form of a walking beam on side wheel 6teamboa‘s. When the vibrations of sound, either by the medium of earth, water, or air, the waves affect the sensitive microphone,and the needle beneath the dial is at once caused to dip. The dipping puts one end of the steel into a diminutive pot of mercury, and a new local current of electricity is started which moves the needle on the face of the dial and serves to give the alarm. The practical workirig of the instrument is inteuded’to do away almost entirely with the picket lines of an army. The instant the air or earth vibrations, caused by the tramp of feet or sound of voices, affect the microphone, that instant the effect is shown on the face of the dial by the turning of the needle from the zero point. - -• -1