ClipArt ETC
"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…

"The angle, ABD, included between the direction of the moving body before it strikes the reflecting surface, and a perpendicular to that surface drawn from the point of contact, is called the angle of incidence. The angle between the perpendicular and the direction of the moving body after striking is called the angle of reflection." -Avery 1895

Law of Reflected Motion

"The angle, ABD, included between the direction of the moving body before it strikes the reflecting…

"The reflecting telescope has an objective a concave mirror, tecnically called a speculum. The images formed by the speculum are brought to the eyepiece in several different ways. Sometimes the eyepiece consists of a series of convex lenses placed in a horizontal tube." — Avery, 1895

Reflecting Telescope

"The reflecting telescope has an objective a concave mirror, tecnically called a speculum. The images…