ON PNEUMATIC MACHINES. 



273 



[of water with which they come in contiguity. To accelerate the draught, 

 the steam ejected from the cylinder, which has still considerable force, is 

 emitttyl up the chimney, thus producing a rapid current in that direction. 

 A section of the engine is given in figure (4.)* 



* From Tredgold's work on the Steam Engine, edited by Woolliouse, 2 vols. 4to, 



