This device was originally intended by Galloway to be used for marine screw propulsion; he also designed 2 and 4 toothed versions, one to develop 300 horsepower. Notice that the volume between the teeth alternately increases and decreases, which makes possible its use for this purpose-although it is not known just how the inventor proposed to provide pressure tight packing.
(H. Roehl, c. 1950)

Francis Moon 2001-00-00