Davis's manual of magnetism : including galvanism, magnetism, electro-magnetism, electro-dynamics, magneto-electricity, and thermo-electricity (1854)
Davis, Daniel · Boston : Palmer and Hall · leaf 295
o-Electric Machine. —An improved form of the machine is represented iaFig. 174. Two straight armatures, surrounded bycoils of insulated copper wire, revolve between twoU-magnets, according to Dr. Pages plan ; but muchshorter armatures are used than in the machine con-trived by him. The steel… … one on each side of a vertical shaft, in such a man-ner that both shall be passing between the oppositepoles at the same time. They are made to revolverapidly by a multiplying wheel, as in Fig. 173. Apole-changer on the shaft conveys the alternatingcurrents in a constant direction to the…
