The detailed quantitative theory of a symmetrical, four carrier, electrostatic voltage multiplier is developed. It is shown that a machine of this type steps up a given applied d.c. potential in a definite ratio, and a formula for this (transformation) ratio is deduced in terms of the coefficients of capacity and the coefficients of induction of the elements of the machine in a definite configuration. A formula which gives the potential of the receivers every geometrical cycle (quarter turn) is deduced. While the current furnished by a device of this sort is extremely small, it may be used separately to excite an ordinary static machine, so that this machine will give a constant current at a constant high potential.