AXIS, in Mechanics. The axis of a balance is that line about which it moves, or rather turns about. Axis of oscillation is a right line parallel to the horizon, passing through the centre, about which a pendulum vibrates.
AXIS in Peritrochio (περίτροχιο, about, and τροχός, a wheel), one of the six mechanical powers, consisting of a peritrochium or wheel concentric with the base of a cylinder, and moveable together with it about its axis. See MECHANICS.