l'KKSIDI-:XTl.\I. ADDRKSS SK(TI()\ A. (jj 



small fraclioii of the world's pctrtjl rc(|uirciiicnis. There are 

 several reasons why benzol cannoi to any extent take the place 

 of petrol, and apart from this, it sufters from the great economic 

 disadvantage that it is the product of a wasting asset — coal. 



l'\)r a considerable number of years many have endeavoured 

 to utilise alcohol, which is derived from the fermentati(ni of 

 vegetable products, but there are two main considerations with 

 regard to its use : 



{I) The flash point is too high (O5 ' F.j to enable it to 

 form an explosive mixture, so that the addition of some in- 

 gredient to lower the flash point is necessary in order that the 

 motor may start easily, especiall\- in cold weather. 



(2) Alcohol, being an intoxicant, is subject to excise regu- 

 lations, to avoid which some denaturaut. or unpalatable sub- 

 stance must be added to it to make it undrinkable. If the 

 denaturant at the same time is such that the flash point is 

 reduced, and the calorific value increased, both requirements 

 would be simultaneously met, and there would be a considerable 

 advantage. 



The importance of alcohol as a motor fuel is such that at 

 the Imperial Motor Transport Conference, held in July, 1913, 

 the following resolution was unanimously passed : — 



" Having regard to the high price of petrol, the limited 

 ([uantities of petrol, coal and oil shales available, and the obvious 

 fact that all these sources of hydrocarbons are in process of 

 depletion, it is advisable that attention be given to the con- 

 struction of motors for alcohol fuel, and that concurrently 

 action should be taken with the view to the ultimate creation of 

 an adequate supply of this fuel, obtainable at sufficiently low 

 price." 



An important series of tests were carried out by the United 

 States Government in 191 2, and the results of over 2,000 com- 

 parative tests are contained in a report by the Bureau of Mines. 

 Ordinary methylated spirit — having Ihe composition Ethyl 

 Alcohol 100 parts, Methyl Alcohol 10 parts, and }4 part of 

 benzine — was used in low speed single cylinder engines. One 

 of the important results arrived at was that explosive mixtures 

 of alcohol vapour and air could be compressed in an engine 

 cylinder to a much higher pressure, without pre-ignition, than 

 explosive mixtures of petrol and air ; with alcohol the com- 

 pression could safelv attain to 180 to 200 lbs. as compared with 

 the safe compression of 70-90 lbs. in the case of petrol. 



Another important noint is that alcohol requires little inore 

 than half the amount of air necessary in the case of petrol for 

 complete combustion, with corresponding less heat wasted in 

 heating, and, further, more complete combustion is obtained 

 than in the case of petrol, so that for equal compression ratio 



