Spon, Ernest, Haldane, Robert, Lock, Charles G. Warnford (Charles George Warnford), 1853-1909 · London ; New York : E. & F.N. Spon · leaf 177
For if a small piece of carbon is struck, telephone work, I prefer the gravity and is the cause of the metallic noise so Daniell battery to any other, but 1 in- often heard in microphones. The length tend to try the iron perchloride battery. of the leaden tube should be 1-& in. (H. B. T.… … 4 holders are glued to the sound-board, a screw g, filed to a square, and moved and, when dry, the pencils are put in by a key. This rubber-ring acts as a place loosely by placing the remaining damper, and prevents noise and rattling. 4 holders. Connections of copper wire, The sound-board is…
Workshop recipes · Technology · Industrial arts
Internet Archive · Getty Research Institute · Public domain (published before 1931). Free to use for anything.
![An illustration from [Graphophone patents] (1878)](https://img.insideoutlibrary.com/img/200/ia-graphophonepaten07unit-917-590.webp)
