SCIENCE AND INDUSTRY. 
intention being to work from 60 Ibs. per square inch down to atmo- 
spheric pressure. The engine was equipped with a high-tension 
magneto, and, instead of using a carburettor, the engine was primed 
through the priming valve on the top of the cylinder. In all the experi- 
ments, ordinary methylated spirit was used. 
The compression was gradually reduced, and attempts were made to 
fire the charge. The first indication of any success was a muffled explo- 
sion at 48 Ibs. compression. At 37 lbs. compression the engine gave 
some distinct explosions, and at 34 lbs. fired regularly. The best results 
were obtained between 35 and 25 Ibs. per square inch compression. Sub- 
sequently, it was found by further experiments that the best way to 
reduce the compression was to control the admission of the air without 
altering the length of the connecting rod. ° 
POWER-ALCOHOL: STARTING DIAGRAMS. 
(Kelly and Lewis Engine, 4}-in. x 6-in.) 
280 /bs. 
- Diagram 1.—Priming Charge, 5cc. Alcohol, 
282 /bs. 
The next test was made with a four-cylinder tractor engine, having a 
44-in. bore, 5g-in. stroke. In this experiment a plug was placed in the 
air-intake pipe. ‘The engine, being primed with alcohol and cranked in 
the usual manner, started easily. 
A further trial was then made with a 25 horse-power Vauxhall car 
equipped with a White and Poppy carburettor. A leather disc was 
placed over the air intake on the carburettor, the engine was primed 
with methylated spirit through the priming cocks, and, by crank- 
ing, the four cylinders were started without difficulty. This was all 
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