Bodies vary in respect to their capacity for holding or accumulating electricity. The electrostatic unit of capacity is the capacity of a conductor that requires a charge of one unit of electricity to raise its potential from zero to unity. It has no special name. A sphere of one centimeter radius has unit capacity. The capacities of spheres are proportional to their radii. (a.) A small conductor (e.g., a sphere the size of a pea) will require less than one unit to raise its potential from 0 to 1 ; it is of small capacity. A sphere five meters in diameter will require many units to raise its potential from 0 to 1 ; it is of great capacity. In other words, the electrostatic capacity of a conductor or condenser is measured by the quantity of electricity which must be imparted to it in order to raise its potential from 0 to 1.