i2 4 SCIENCE PROGRESS 



sq. in. is about the limit. After the war petrol will hardly go below 2s. per 

 gallon, which is about the pre-war cost of alcohol, but it is made quite clear in 

 Mr. Tweedy's book that alcohol could be sold at a much lower price than this if 

 the industry was handled sympathetically and not overburdened by excise re- 

 strictions. The advantages of alcohol as a fuel, as compared with petrol, are 

 (a) smoother running, (b) absence of carbonisation, (c) absence of unpleasant 

 exhaust, (d) greater safety from fire owing to its miscibility with water. On the 

 other hand, it is not suitable for high-speed engines and will not start from 

 the cold, so that either an auxiliary petrol tank and carburettor are required or 

 some heating device must be used. During the transition stage from petrol 

 to alcohol it may be desirable to overcome the difficulty by mixing alcohol with 

 some other liquid fuel, such as benzine or sulphuric ether. This would both 

 overcome the difficulty in starting from the cold and also enable existing engines 

 to be used without alteration. 



