440 



Oil Encunes. 



temperature necessary for the ignition of the charge. Means 

 are provided for maintaining the proper temperature with a full 

 or with light load, although the heat due to combustion may 

 vary through a considerable range. Ingenious devices are also 

 used by means of which the total capacity of the spaces into 

 which the air and vapour have to be compressed may be changed 

 to suit the different kinds of oil that may be used. 



The initial heating of the vapouriser is effected by means of 

 an oil lamp of the Bunsen burner type, requiring no fan for 

 its operation. It takes from 8 to 12 minutes to heat the 



Fig. 2.— Hornsey-Ackroyd Oil Engine (50 h.p). 



vapouriser sufficiently to start the engine with the ordinary 

 petroleum oils, such as Royal Daylight, Tea Rose, Water 

 White, or the heavier oils, such as Russolene. In a slightly 

 modified engine the cheaper Texas oil may be used. The cost 

 of the oil as fuel for these and other oil engines may be taken 

 as a secondary consideration, whether with reference to the 

 small engines chiefly used for agricultural and estate work or 

 for larger sizes. These engines are all of the horizontal cylinder 

 type, one of which, as made for using the cheaper crude or 

 semi-crude petroleums, is shown by Fig. 2, which is from a 

 photograph of a 30 brake horse-power engine. From it 

 will be seen the position of the oil pump taking oil frcm the 



