ClipArt ETC
"A much better form of electromagnetic ammeter can be constructed on a principle now extensively employed, which consists in pivoting in the strong field of a permanent magnet a small coil through which a part of the current to be measured is sent." —Encyclopedia Britannica, 1910

Shunted Movable Coil Ammeter

"A much better form of electromagnetic ammeter can be constructed on a principle now extensively employed,…

Movable canon on wheels.

Cannon

Movable canon on wheels.

Typically consists of three or four doors that hang on a center shaft and rotate around a vertical axis within a round enclosure.

Rotating Door

Typically consists of three or four doors that hang on a center shaft and rotate around a vertical axis…

"An electrodynamometer is a galvanometer with two coils, at least one of which is movable, and through at least one of which the curent to be measured passes. It is very useful in the measurement of alternating curernts and voltages." -Avery 1895

Electrodynamometer

"An electrodynamometer is a galvanometer with two coils, at least one of which is movable, and through…

F, fixed coil; D, movable coil; S, spiral spring; T, Torsion head; MM, Mercury cups; I, Index needle.

Siemens Electrodynamometer

F, fixed coil; D, movable coil; S, spiral spring; T, Torsion head; MM, Mercury cups; I, Index needle.

"A pulley is a wheel having a grooved rim for carrying a rope or other line, and turning on an axis carried in a frame, called a pulley block. The pulley is movable if the block moves during the action of the power." — Avery, 1895

Movable pulley

"A pulley is a wheel having a grooved rim for carrying a rope or other line, and turning on an axis…

"In the single moveable pulley, the same rope passes from the fixed point, A, to the power, P. It is evident here, that the weight, W, ten pounds, five pounds will be supported by one string, and five by the other. The power will then support twice its own weight." -Comstock 1850

Single Movable Pulley

"In the single moveable pulley, the same rope passes from the fixed point, A, to the power, P. It is…

"The wedge is a movable inclined plane, and is used for moving a great weight a short distance. A common method is shown here." —Hallock 1905

Wedge

"The wedge is a movable inclined plane, and is used for moving a great weight a short distance. A common…

"Features six movable pulleys aligned on the same axis. This pulley was invented to reduce the friction of each block to a single wheel." —Quackenbos 1859

White's Pulley

"Features six movable pulleys aligned on the same axis. This pulley was invented to reduce the friction…