"Machine designed by Atwood to allow the measurement and calculation of the velocities of falling bodies at various points accurately and easily." —Quackenbos 1859

Atwood's Machine

"Machine designed by Atwood to allow the measurement and calculation of the velocities of falling bodies…

"Where five blocks are placed in this position, the point of gravity is near the centre of the thrd block, and is within the base as shown by the plumb line. But on adding another block, the gravitation point falls beyond the base, and the whole will now fall by its own weight." -Comstock 1850

Center of Gravity of Standing Blocks

"Where five blocks are placed in this position, the point of gravity is near the centre of the thrd…

"While treading on our course this earthly ball, / We often stumble, and we sometimes fall: / 'Get above others.' says human nature, / But if we get too high, the fall is greater. / He that would 'scape great dangers far and nigh, / Will lowly walk, and will not climb too high."—Barber, 1857

Climb Not Too High, Lest the Fall be Greater

"While treading on our course this earthly ball, / We often stumble, and we sometimes fall: / 'Get above…

"In a vacuum, all bodies fall at the same rate." -Comstock 1850

Falling Bodies in a Vacuum

"In a vacuum, all bodies fall at the same rate." -Comstock 1850

"When a feather and a cent are dropped from the same height, the cent reaches jthe ground first. this is not because the cent is heavier, bu because the feather meets with more resistance from the air in proportion to its mass. If this resistance can be removed or equalized, the two bodies will fall equal distances in equal times, or with the same velocity. The resistance may be avoided by dropping them in a glass tube from which the air has been removed. The resistances may be nearly equalized by making the two falling bodies of the same size and shape bu of different weights, as in the preceding experiment." -Avery 1895

Velocities of Falling Bodies

"When a feather and a cent are dropped from the same height, the cent reaches jthe ground first. this…

Jack and Jill went up the hill to fetch a pail of water. Jack fell down and broke his crown, and Jill came tumbling after.

Jack and Jill

Jack and Jill went up the hill to fetch a pail of water. Jack fell down and broke his crown, and Jill…

Jack and Jill went up the hill to fetch a pail of water. Jack fell down and broke his crown, and Jill came tumbling after.

Jack and Jill

Jack and Jill went up the hill to fetch a pail of water. Jack fell down and broke his crown, and Jill…

An illustration of Sir Isaac Newton sitting on the ground being hit by an apple falling out of a tree and discovering the law of gravity.

Isaac Newton Discovering Gravity

An illustration of Sir Isaac Newton sitting on the ground being hit by an apple falling out of a tree…

"The child is wandering into danger great, / The mother draws it from a downward fate, / Thus stops its fall; better thus 'tis quite plain, / Than broken limbs to have, and hours of pain. / Would you prevent a man from drinking rum, / Destroy his liquor, and the work is done."—Barber, 1857

Prevention is Better than Cure

"The child is wandering into danger great, / The mother draws it from a downward fate, / Thus stops…

"Suppose a cannon be loaded with a ball, and placed on top of a tower, at such a height from the ground, that it would take just three seconds for the ball to descend from it to the ground, if let fall perpendicularly. Now, suppose the cannon to be fired in an exact horizontal direction, and at the same instant, the ball to be dropped towards the ground. They will both reach the ground at the same instant..." -Comstock 1850

Projectile Motion of a Cannonball

"Suppose a cannon be loaded with a ball, and placed on top of a tower, at such a height from the ground,…

"Three children sliding on the ice, All on a summer's day. As it fell out they all fell in. The rest they ran away."

Three Children

"Three children sliding on the ice, All on a summer's day. As it fell out they all fell in. The rest…