"In the Deprez-d'Arsonval dead-beat galvanometer, a moveable coil is suspended between the poles of a string, permanent U-magnet that is fixed. The coil consists of many turns of fine wire the terminals of which above and below serve as the supporting axis. Within the coil is an iron tube that is supported form the back, and that serves to concentrate the magnetic field. The passage of current turns the coil, and sets it so that its plane encloses a larger number of liens of force. this movement of the coil turns the mirror by means of which the angles of deflection are read with a telescope and scale." -Avery 1895

Deprez-d'Arsonval Dead-Beat Reflecting Galvanometer

"In the Deprez-d'Arsonval dead-beat galvanometer, a moveable coil is suspended between the poles of…