FIG. 17.—PIXII MAGNETO-ELECTRIC MACHINE, 1832.
Saxton in the United States and Pixii in France were the first to produce organized devices of this class for generating electricity from magnetism. Pixii’s machine (1832) consisted of a permanent horse-shoe magnet which was caused to revolve in proximity to an armature upon which was wound a coil of insulated wire. On March 30, 1852, Sonnenberg and Rechten obtained a United States patent, No. 8,843, for an electrical machine for killing whales, and on August 19, 1856, Shepard obtained U. S. Pat. No. 15,596 for the machine which came to be known as the “Alliance” machine. Both of these machines had permanent field magnets, and were early types of magneto-electric machines. The efficiency of these magneto-electric machines was necessarily limited to the strength of the inducing field magnets, which, being permanent magnets, were a positive and fixed factor. It was an easy step to substitute electro-magnets for permanent magnets, as the field or inducing magnets, and also to excite the (electro) field magnet by voltaic batteries, but the important step which resulted in the machine which is called the “dynamo” (from the Greek “Δυναμις”—power) was yet to come.
FIG. 18.—HJORTH’S DYNAMO ELECTRIC MACHINE.
FIG. 19.—HJORTH’S DYNAMO ELECTRIC MACHINE, PLAN VIEW.