ClipArt ETC
Illustrations showing the six mechanical powers: lever, wheel and axle, pulley, inclined plane, wedge, and screw.

Simple Machines

Illustrations showing the six mechanical powers: lever, wheel and axle, pulley, inclined plane, wedge,…

"...represents a simple pulley, with a single fixed wheel. In other forms of the machine, the wheel moves up and down with the weight." -Comstock 1850

Simple Pulley

"...represents a simple pulley, with a single fixed wheel. In other forms of the machine, the wheel…

"Two fixed pulleys used to raise W." -Comstock 1850

Simple Pulley

"Two fixed pulleys used to raise W." -Comstock 1850

"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…

"A machine for turning a roasting-spit by means of a fly-wheel or -wheels, set in motion by the current of ascending air in a chimney. a,a, the chimney, contracted in a circular form; b, strong bar placed over the fireplace, to support the jack; c, wheel with vanes radiating from its center, set in motion by the ascent of the heated air, and communicating by the pinion d and the crown-wheel e, with the pulley f, from which motion is transmitted to the spit by the chain passing over it." —Whitney, 1889

Smoke-Jack Used for Roasting Meat

"A machine for turning a roasting-spit by means of a fly-wheel or -wheels, set in motion by the current…

"A block used in ships, having an opening in one side to receive the bight of a rope, chiefly used for heavy purchases, where a warp or hawser is brought to the capstan." — Williams, 1889

Snatch-block

"A block used in ships, having an opening in one side to receive the bight of a rope, chiefly used for…

"A machine for spinning flax into threads by hand. It consists of a wheel, band, and spindle, and is driven by foot or by hand...a, bench or stool; b, standards; c, driving band wheel grooved in its perimeter; d, treadle; e, rod which connects treadle with crank; f, cord-band which drives the flier-spindle; g, flier; h, distaff upon which the flax to be spun is placed, and which in use is held in the left hand of the operator." —Whitney, 1889

Spinning Wheel for Flax

"A machine for spinning flax into threads by hand. It consists of a wheel, band, and spindle, and is…

"A machine for spinning flax into threads by hand. It consists of a wheel, band, and spindle, and is driven by foot or by hand...a, bench; b, b1, standards; c, driving band-wheel with flat rim, turned by the peg k held in the right hand of the spinner; d, cord-band, crossed at e and driving the speed-pulley f; g, cord-band imparting motion to the spindle h; i, thread in process of spinning." —Whitney, 1889

Spinning Wheel for Wool

"A machine for spinning flax into threads by hand. It consists of a wheel, band, and spindle, and is…

"The following description of a section of Lord Rosse's telescope, though not so perfect as could be desired, is the best we could obtain. it exhibits a view of the inside of the eastern wall, with the tube, and machinery by which it is moved. A is the mason-work on the ground; B the universal joint, which allows the tube to turn in all directions; C the speculum in the tube; E the eye-piece through which the observer looks; F a pulley by which the tube is moved; H a chain attached to the pulley, and to the side of the tube; I, a chain running to K, the counterpoise; L, a lever connecting the chain M with the tube; Z another chain which passes from the upper part of the tube over a pulley at W, (not seen) and crosses to the opposite wall; X a railroad on which the speculum is drawn either to or from the tube. The dotted line H, shows the course of the weight R, as the tube rises or falls. The tube is moved from wall to wall by a ratchet wheel at R, which is turned by the lever O, on the circle N, the ends of which are fixed in the two walls." —Comstock, 1850

Telescope

"The following description of a section of Lord Rosse's telescope, though not so perfect as could be…

Three cylindrical weights, suspended on ropes and pulleys.

Weights and Pulleys

Three cylindrical weights, suspended on ropes and pulleys.

"To change the direction, it is only necessary that the rope by which the weight is to be raised, should be carried in a line perpendicular to the axis of the machine, sto the place below where the weight lies, and there be let fall over a pulley." -Comstock 1850

Wheel and Axle

"To change the direction, it is only necessary that the rope by which the weight is to be raised, should…

"The whole length of the tube of the wheel barometer, from C to A, is 34 or 35 inches, and it is filled with mercury, as usual. The mercury rises in the short leg to the point a, where there is a small piece of glass floating on its surface, to which there is attached a silk string, passing over the pulley p. To the axis of the pulley is fixed an index, or hand, and behind this is a graduated circle, as seen in the figure. It is obvious, that a very slight variation in the height of the mercury at o, will be indicated by a considerable motion of the index, and thus changes in the weight of the atmosphere, hardly perceptible by the common barometer, will become quite apparent by this." —Comstock, 1850

Wheel Barometer

"The whole length of the tube of the wheel barometer, from C to A, is 34 or 35 inches, and it is filled…

"In order that the successive wheels should revolve in the same time, and their circumfrences should be just equal to the length of rope passing between them...By this construction, although the length of rope passing over each was different, yet their revolutions are equal, both with respect to time and number." -Comstock 1850

White's Pulley

"In order that the successive wheels should revolve in the same time, and their circumfrences should…

"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…