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 324
ents of whichthe extremities of the wire are soldered. The springspressing on these segments convey the currents tothe screw-cups on the base board. When the cupsare connected with those of a delicate galvanometer,and the instrument placed in such a direction thatthe helix shall move in the… … are induced in the wire, their direction changingas the helix passes this point. 506. These alternating currents of electricity areturned into one course by the pole-changer, the seg-ments of which may be so arranged as to pass fromone spring to the other when the helix is vertical,this being…
