"Two cannon balls, when suspened by long cords, so as to hang quite near each other, are found to exert a mutual attaction, so that neither of the cords are excatly perpendicular, but they approach each other..." -Comstock 1850

Gravitational Attraction

"Two cannon balls, when suspened by long cords, so as to hang quite near each other, are found to exert…

"If an excited substance be brought near a ball made of pith, or cork, suspended by a silk thread, the ball will, in the first place, approach the electric, as at a, indicating an attraction towards it, and if the position of the electric will allow, the ball will come into contact with the electric, and adhere to it for a short time, and whill then recede from it, showing that it is repelled, as at b." -Comstock 1850

Electrical Attraction

"If an excited substance be brought near a ball made of pith, or cork, suspended by a silk thread, the…

"b is a glass tube in water and c is a glass tube in mercury. The surface of the water in the tube b is concave, while the surface of the mercury in the tube c is convex." — Hallock, 1905

Capillary Attraction

"b is a glass tube in water and c is a glass tube in mercury. The surface of the water in the tube b…

"Pith ball pendulum or electroscope; the figures illustrate also electrical attraction and repulsion." -Hawkins, 1917

Electroscope Attraction and Repulsion

"Pith ball pendulum or electroscope; the figures illustrate also electrical attraction and repulsion."…

"Mutual action of solenoids. When two solenoids traversed by a current are allows to act on each other...attraction and repulsion will take place just as in the case of two magnets." -Hawkins, 1917

Solenoid, attraction

"Mutual action of solenoids. When two solenoids traversed by a current are allows to act on each other...attraction…