The subject of this paper is the jet-wave rectifier, a purely mechanical device which, in the course of the last 15 years, has been developed into a means for high-power rectification. Prototypes of the constituent parts of the apparatus have been described elsewhere; in the present paper it is shown how the rectifier can be designed on the basis of these prototypes, and especially on the result of investigations with regard to the theoretical relations between their qualities. These relations are stated and are used in working out examples of typical designs. In addition, a review of the general properties of the jet-wave rectifier, and anticipations with regard to its future development, are given. It is concluded that a new high-capacity rectifier, of a character quite distinct from that of the mercury-arc rectifier, but likely to be used for similar duties, has been brought into existence.