American telegraphy and encyclopedia of the telegraph; systems, apparatus, operation (1909)
Maver, William, jr. [from old catalog] · New York, Maver publishing company · leaf 383
mitter isindicated by r; the projections which reach to the ends of the carbon discs by e <?;the rod and armatures of the receiver by r and a a. It is well known that the electrical resistance of carbon varies under pressure, theresistance decreasing as the pressure is increased. This fact, as… … C 11
Telegraph
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer02inte-161-68.webp)
![An illustration from [Electric engineering.] (1902)](https://img.insideoutlibrary.com/img/200/ia-electricengineer03inte-406-255.webp)
