776 



REPOET 1891. 



separate combustion-chamber, or where tlie air is heated through an intervening 

 metallic diaphragm. The drawing up of tlie grit and ashes is completely prevented 

 in the present motor, this latter feature forming an important part of the invention. 



As will be seen by the drawings, the engine is constructed on the beam prin- 

 ciple, and the combustion-chamber is really a prolongation of the working cylinder. 



The piston (or plunger) is of considerable length, the upper part only being 

 made to fit the cylinder. The lower part of the piston is of slightly less diameter, 

 consequently an annular space is formed between it and the cylinder. This space 

 is connected with the main air-supply, which is controlled by a valve operated by 



a connecting-rod and cam-lever worked from a cain on the crank-shaft of the 

 engine. The air-pump is placed in the centre of the machine, immediately beneath 

 the beam-standard, and is operated by a rod attached to the rocking-beam, and 

 this is connected by a rod to the crank-shaft. Owing to the position of the beam, 

 pump, and connecting-rods, the piston of the air-pump is at the outer end of its 

 stroke when the working piston, on its return stroke, has reached a middle position. 

 During the last half of the return stroke of the working piston the air-piston is 

 pushed inwards, and compresses the charge of air previously drawn in until it has 

 reached the middle of the stroke, at which moment the working piston is at the 



