This pulley arrangement gives a mechanical advantage of 2; for the lower, movable pulley may be regarded as an endless lever of the second order.

Pulley System

This pulley arrangement gives a mechanical advantage of 2; for the lower, movable pulley may be regarded…

This figure has six pulleys and one cord passes round them all. Each pulley is stretched with the same amount of force, which is equal to the power creating a mechanical advantage of 6.

Pulley System

This figure has six pulleys and one cord passes round them all. Each pulley is stretched with the same…

This arrangement have three movable pulleys, each hanging by a separate cord. The mechanical advantage is 8.

Pulley System

This arrangement have three movable pulleys, each hanging by a separate cord. The mechanical advantage…

"A pump for exhausting air and other gases from a closed space, or for compressing air within an enclosed space." -Foster, 1921

Air Pump

"A pump for exhausting air and other gases from a closed space, or for compressing air within an enclosed…

"The stick AB appears bent at C, on account of the refraction caused by the water. The eye sees the end B in the direction of the refracted ray, and it appears at D instead of where it really is." -Foster, 1921

Refraction

"The stick AB appears bent at C, on account of the refraction caused by the water. The eye sees the…

The screw is the case of the inclined plane, with the length of one convolution of the thread being the length of the corresponding inclined plane.

Screw

The screw is the case of the inclined plane, with the length of one convolution of the thread being…

In the screw press, the screw is turned by means of a lever, which gives a great increase of mechanical advantage.

Screw Press

In the screw press, the screw is turned by means of a lever, which gives a great increase of mechanical…

In the second order of levers, the weight is between the power and the fulcrum.

Second Order of Lever

In the second order of levers, the weight is between the power and the fulcrum.

"A glass vessel used to separate liquids which differ in specific gravity and are not miscible." -Whitney, 1911

Separator

"A glass vessel used to separate liquids which differ in specific gravity and are not miscible." -Whitney,…

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,…

The siphon is an instrument in which a liquid, under the combined action of its own weight and atmospheric pressure, flows first uphill and then downhill.

Siphon

The siphon is an instrument in which a liquid, under the combined action of its own weight and atmospheric…

A Siphon can be started by inserting one end of a tube in the liquid and sucking at the other end. It is more convenient to apply suction by means of a side tube as shown to prevent the liquid from entering the mouth.

Starting the Siphon

A Siphon can be started by inserting one end of a tube in the liquid and sucking at the other end. It…

"C. Collimator; P, center of group of prisms; T, telescope; s, slit through which the ray of light enters, R, ray on its progress through prisms to telescope."—Finley, 1917

Spectroscope

"C. Collimator; P, center of group of prisms; T, telescope; s, slit through which the ray of light enters,…

Three spring-balances hooked together around a small ring.

Spring-balances

Three spring-balances hooked together around a small ring.

"The Steelyard is more portable then the ordinary balance. It consists of a lever, AB, moving round a knife-edge or point at C. The body to be weighed, W, is put into the scale which hangs from A; and a movable weight P, is made to slide along the longer arm, until the lever, AB, remains horizontal." — Chambers' Encyclopedia, 1875

Steelyard

"The Steelyard is more portable then the ordinary balance. It consists of a lever, AB, moving round…

The steelyard is an instrument for weighing bodies by means of a single weight which can be hung at any point of a graduated arm.

Steelyard

The steelyard is an instrument for weighing bodies by means of a single weight which can be hung at…

The suction-pump consists of a clindrical pump-barrel traversed by a piston, and communicating by means of a suction-tube with the water in the pump-well.

Suction-pump

The suction-pump consists of a clindrical pump-barrel traversed by a piston, and communicating by means…

A suction-pump with the upward and downward movement of the piston being effected by means of a lever.

Suction-pump

A suction-pump with the upward and downward movement of the piston being effected by means of a lever.

A suction-pump in which the alternate motion of the piston is effected by means of a rotary motion.

Suction-pump

A suction-pump in which the alternate motion of the piston is effected by means of a rotary motion.

In the third order of levers, the power is between the weight and the fulcrum.

Third Order of Lever

In the third order of levers, the power is between the weight and the fulcrum.

This experiment showed that every surface exposed to the atmosphere sustains a normal pressure equal to the weight of a column of mercury whose base is this surface and whose height is 30 inches.

Torricellian Experiment

This experiment showed that every surface exposed to the atmosphere sustains a normal pressure equal…

Trajectory is the path a moving object follows through space. A trajectory can be described mathematically either by the geometry of the path, or as the position of the object over time.

Trajectory

Trajectory is the path a moving object follows through space. A trajectory can be described mathematically…

A tube open at both ends with the lower end covered with a piece of card, plunged into the water. The liquid will press the card against the bottom of the tube with a force which increases as it is plunged deeper.

Upward Pressure

A tube open at both ends with the lower end covered with a piece of card, plunged into the water. The…

As you pour water into a Cup of Tantalus, the cup fills with water, but after it reaches a certain height, the water begins to drain through the siphon.

Vase of Tantalus

As you pour water into a Cup of Tantalus, the cup fills with water, but after it reaches a certain height,…

"A loaded vehicle is represented as crossing the side of a hill, which has been raised one wheel above the level of the other wheel, so as to incline the body of the vehicle very considerably from the horizontal. The centre of gravity is represented in two different positions; a lower one with th eline of direction L C, and a higher one with the line of direction U C. If there had been no load upon the vehicle, the line of direction would have remained at L C; and as it falls within the wheel, or base, the vehicle would have maintained its balance. But if the wagon had been laden, the centre of gravity would have been raised, and, the line of direction U C consequently falling without the wheel, the vehicle must overturn." — Goodrich, 1844

Vehicle on hill

"A loaded vehicle is represented as crossing the side of a hill, which has been raised one wheel above…

The instrument called the water-level illustrates the principle of equilibrium in vessels communicating with each other.

Water-level

The instrument called the water-level illustrates the principle of equilibrium in vessels communicating…

This experiment filled globe alternately with ordinary air and comnpressed air to determine the weight of air.

Weight of Air

This experiment filled globe alternately with ordinary air and comnpressed air to determine the weight…

Three cylindrical weights, suspended on ropes and pulleys.

Weights and pulleys

Three cylindrical weights, suspended on ropes and pulleys.

The wheel barometer consists of a siphon barometer, the two branches of which have usually the same diameter.

Wheel Barometer

The wheel barometer consists of a siphon barometer, the two branches of which have usually the same…