OrL Engines. 



457 



of the automatic ignition type, but provided with an ignition 

 tube heated by an external lamp, which at the same time heats 

 the separate combustion chamber. After starting the lamp is 

 extinguished. In principle the engine is similar to that of 

 several of those already described, but in detail it differs in 

 important respects. No oil pump is used, the oil being sucked 

 up as required on the suction stroke of the piston, the quantity 

 varying automatically with the governor control of the vapour 

 valve between the vapouriser and the combustion chamber. The 

 vapouriser is of the vertical baffled path type, separated from 

 the cylinder by a neck carrying the air inlet valve, the position 

 and cooling effect of which are adopted as the means of pre- 

 venting the pre- ignitions otherwise likely to occur, especially 

 with a sufficiently high compression for economical working. 



Fig. 1 8 is from a photograph of the <( Kynoch " portable engine, 

 which is well made and of several sizes. Trials made at the 

 works of the makers of one of these engines of ^b.h.p. are said 

 to have shown a consumption of only Q'6/5 lb. of oil, viz., 

 Russolene, per b.h.p., although the mechanical efficiency was only 

 70 per cent. 



Among other makers of engines of the automatic ignition 

 class are Messrs. Edward Humphreys & Co., in whose engine, the 

 " Atlas," a pump is employed to force the oil into a spray box, 

 the quantity of oil injected being controlled by a governor. 

 The spray is received in the combustion space near the air 

 admission valve, and on maximum compression is fired by an 

 internal ignition tube, the temperature of which is maintained 

 by the heat from combustion absorbed by a cast iron inwardly 

 projecting hat, forming part of the combustion chamber and 

 carrying the tube. 



The Newton Electrical Works Company, Taunton, and Messrs 

 Fetter & Sons, Yeovil, are also makers of engines of the smaller 

 sizes in this class. 



An engine differing in construction from any of those described, 

 and which has the merit of being economical on half load, is the 

 Robey-Saurer engine made by Robey & Co. It is of the exterior 

 vapouriser, ignition tube and heating lamp type, and is easily 

 accessible in all its parts. The vapouriser is of simple form, the 

 oil is supplied to it by a small governor-controlled pump, and a 



