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 135
ts the current by breaking the contact be-tween the cylindrical part of the axis and the spring,and the coil falls back to its first position. As thewheel moves on, the other spring comes in contactwith the axis, causing the other coil to be charged,and to go through the same movements. The qoil«… … ed upon wheels, pass over the legs of a steel magnetfixed in a horizontal position, the wheels movingupon inclined rails. When the instrument is con-nected with the battery, the coils become charged,and move along the poles towards the bend of themagnet. The battery connections must be so madethat…
