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 196
18is seen a revolv-ing circle, composedof two semicircularbars, the shaded oneof iron, the otherof brass. This cir-cle is supported byfour grooved fric-tion rollers, so as to move freely within the twocoils. Its circumference is cut into teeth, and its mo-tion is communicated to two smaller toothed… … 180 D AVI S S MANUAL. current is interrupted; and, as it moves on by itsacquired momentum, the action of the break-piececauses the other helix to be charged, and the ironto be drawn into it. 288. Vibrating Helix. —Instead of a oar movingwithin the helix, the latter may be made to move 2?Yo.. 1X9.…
