The idea was conceived that a tliree cylinder screw ens^ine could 

 he made V>y turning the boss of the propeller into an engine, thus 

 allowing the cylinders to revolve on the crank-shaft, the shaft and 

 crank-pin being stationary and the thrust coining direct on the 



speed, resulting in the production of the predecessor of Fig. o, 

 which weighed l of a pound, tliis worked so satisfactorily that 

 after some kindred experiments were made Fig. o came into 

 existence, weighing only 7.', ounces, and taking the first live 

 seconds of the diagram. (Fig' 6) we see that the revolutions are at 

 the rate of 4.^6 per minute, the receiver pressure falling from 

 IDOlTjs to about 1201hs. The cvlinders are -HS inches diameter: 

 the stroke is 1-3 inches and theValve cuts off" at woof the stroke. 

 The .screw blades are set .-.t an angle of 20' giving a pitch of U'i 

 inches, the diameter of the sci'(;w is 3(5 j inches, and the area of 

 «ich blade is 32-7 wjuare inches. 



this ei\gine to far surpass the india rubber driviMi screw as a motor. 



which assume such varied forms in the hands of experimentalists. 



The air receivers for these motors are made of ordinaiy tin- 



.■^inith's tinned iron plate, the thickness of plate in the receiver t'oi' 



along the plate of ()-i,()(K)tT)s pvv s(iuarc inch section of metal -n •"' 



the weight is 29 ounces and ir h.asbi.en pr.-.c,] t„ -.Mi |„,u,Mi- \n'V 



