"Little children, let no man deceive you: he that doeth righteousness is righteous, even as he is righteous."—1 John iii.
865. Why can the little boy, if he choose, keep the big boy up, when once he is up?
Because, as the big boy is then on an inclined plane with the fulcrum, or centre upon which the see-saw moves, the arm of the lever, upon which the big boy sits, is relatively shortened, and he has then less mechanical power. Also, a portion of the weight of the larger boy is transmitted along the lever to the arm upon which the little boy sits.
Fig. 45.—TRAP AND BALL.
866. Why is the ball propelled upward, in the game of trap and ball, when the trigger is struck?
Because, when the trigger is struck at A, it is forced downwards, turning upon the fulcrum B, the opposite end, forming the spoon, is thereby forced upwards, describing a small arc, or curved line; but directly the ball is set free from the spoon, it rises in a right line with the direction it was taking, at the moment it was set free.