Dynamos and motors; a text book for colleges and technical schools (1911)
Franklin, William S. (William Suddards), 1863-1930, Esty, William, 1868-1928 · New York The Macmillan company · leaf 296
Fig. 208a. Fig. 208b. bulb DD containing a pool of mercury C and a graphite elec-trode A. The bulb is highly exhausted and contains onlymercury vapor. A very high electromotive force is required tostart a current in either direction through the mercury vapor, butwhen the current is once established…
Dynamos · Electric motors
Internet Archive · Gerstein Library, University of Toronto · Public Domain Mark 1.0. Free to use for anything.
