The Recent Revolution in Organ Building / Being an Account of Modern Developments

by George Laing Miller

Fig. 23. Diaphone in Worcester Cathedral, Eng.

M is a pneumatic motor or bellows to which is attached a rod bearing the compound and spring valve V, V¹, working against the spring S. On the admission of wind (under pressure) to the box A, the motor M is caused to collapse, and thereby to open the valves V, V¹. Wind then rushes into the chamber B, and entering the interior of motor M through the passage C, equalizes the pressure in the motor. The action of the springs now serves to close the valves V, V¹, and to open out the motor M, whereupon the process is repeated.