Preface xxxi. 



gravity 079 at 59 F.) has a corresponding heat 

 value of 77,274 B.t.u. One pound of 100 per 

 cent, alcohol requires theoretically 9 Ib. of air, 

 or 1 1 1*5 cubic feet, at 62 F., for complete com- 

 bustion. Care must be taken to see that the 

 right quantity of air is given, because if the 

 engine is run on an over-rich mixture acetic 

 acid is produced and causes corrosion of the 

 engine parts. 



" A series of tests have been carried out in 

 the United States with a view to determining 

 whether the petrol engines now in use could be 

 run on alcohol, and what improvements could 

 be effected in the design to render them more 

 suitable. In the trials eight engines ranging 

 from 2 to 40 h.p. were used, three of them 

 being high-speed motor-car engines of which 

 two were of 40 h.p., the other engines being 

 of the internal combustion types such as are 

 used in commercial and agricultural operations. 

 Each of the eight engines was run on alcohol 

 as well as on paraffin and petrol, as many as 

 thirty distinct and separate tests being taken 

 on some of the engines. The alcohol used 

 was virtually the same as that obtainable in 

 this country under the name of methylated 

 spirit, and consisted of 90 per cent, of ethyl 

 alcohol and 10 per cent, of methyl alcohols 

 with about 0*5 per cent, benzine added, the 

 percentages being in volume. Its specific 

 gravity was about O'S^. The petrol used had 

 a specific gravity of 071, which is to say that 



