Angular Velocity
The angle through which an arm turning on its axis is displaced in a unit of time. It is entirely independent of the length of this arm. The approximate ratio of the angular velocities of the balance with the cylinder and (pocket) chronometer escapements in the same unit of time (one-fifth second when there are 18,000 vibrations per hour), is about 270 deg.: 360 deg. The velocity, properly so called, is the space transversed in a unit of time by the point under consideration (which in this case is taken on the circumference of gyration). For a given angular movement we obtain the aproximate ratio of the velocities by multiplying each radius by the number of vibrations in a unit of time.--Saunier.