CATALOGUE OF THE MECHANICAL ENGINEERING COLLECTION. 41 



through the cock and exerts no pressure on the oil which, therefore, 

 can not rise to the nozzle, and the engine stops. 



Cat. No. 251,283 U. S. N.M. 



Model of Julius Hock Petroleum Engine. U. S. Patent, No. 151129, May 

 19, 1874. Transferred from United States Patent Office. 



This is one of the earliest types o.f internal combustion engines in 

 which liquid petroleum is spraj^ed into the cylinder and ignited. Oil 



FIG. 16.- — HOCK OIL ENGINE. THE FIRST SDOCESSFUL ONE, 1874. 



is supplied to the motor from an air-tight tank, the quantity being 

 regulated by raising or lowering a plunger immersed in the oil. The 

 cylinder end of this oil supply pipe is nozzle-shaped and is screwed 

 into the cylinder head. Arranged in the cylinder head also are 

 one or more air nozzles directed across the path of the oil and 

 supplied with air from a bulb similar to that on the Errani and 

 Anders motor. The mixture of oil and air is ignited bj- a flame of 

 gas directed horizontally into the cylinder through a hole in its head. 

 The gas, which is naphtha, is obtained from a generator attached to t[he 

 bulb compressor, which generator consists of a tank containing pe- 

 troleum. Air from the compressor is forced through the petroleum, 

 yielding a mixture of naphtha and carbonized air. A portion of this 



