PRESIDKNTIAL ADDRESS— SPrTION A. 71 



It is worthy uf note that willi the alcohol fuel no trouble 

 whatever was experienced in starting up with the engine either 

 hot or cold, that the deposit in the cylinders and on the pistons 

 and itlugs was considerably less than with petrol, and that, in 

 additinii. ilio exhaust was colourless and odourless. 



Among the advantages claimed for alcohol as a fuel may 

 '■)e mentioned: its greater safety — due to its higher Hash point 

 And low degree of volatilit}'. and the fact that it mixes in all 

 proportions ^vith water, so that burning alcohol may therefore, 

 unlike petrol, be extinguished by water ; it is safer because a 

 greater proportion of vapour in air is reciuired to form an ex- 

 plosive mixture, and further, the density of the vapour being 

 less than half that of petrol, there is not the same tendency for 

 the vapour to accumulate. 



The explosive range of alcohol air mixtures is greater than 

 in the case of petrol, and this gives greater flexibility in run- 

 ning. But one drawback to the replacement of petrol b\- an 

 alcohol fuel, in an ordinary motor-car without increased com- 

 pression, would be that the total mileage capacity would be 

 reduced on account of the greater bulk of fuel required for 

 equal power. 



Probably the main objection urged against the use of 

 alcohol fuels is the fear of corrosion due to the formation of 

 acids. But, as one wn-iter puts it, this is probably a case of 

 " lack of confidence springing from inexperience." It is known 

 that the incomplete combustion of an alcohol leads to the forma- 

 tion of an aldehyde, which in turn forms an acid — acetic acid in 

 the case of Ethyl Alcohol, and formic acid in the case of Methyl 

 Alcohol, or wood spirit. Chemical tests of the condensate from 

 the exhaust gases showed a slight trace of acetic acid, but as the 

 vapourising temperature of this acid is 246° F., and the tem- 

 perature of the exhaust is about 900° F., anv acid formed would 

 pass off Avith the exhaust gas, and the velocity of efiflux would 

 cause its ejection before any chemical action could take place. 

 All published statements, with regard to corrosion, when 

 alcohol is used as a motor fuel, have reference to methylated 

 spirit: that is. Ethyl Alcohol made poisonous or repulsive hy 

 the addition of 10 per cent, of crude methyl alcohol or wood 

 c^piVJt — made by the destructive distillation of wood and condens- 

 ation of the vanours — and small amounts of other obnoxious 

 substances. Methvl alcohol is much more liable to form an acid 

 than ethvl alcohol, and the immunity from acid in this case is 

 probablv due to the small amount (2 per cent.) used in this 

 fuel. Anv corrosive effect which could take place due to the 

 presence of acids would be in the cold exhaust pipe and silencer 

 after shutting down. The risk of corrosion can best be determined 

 bv practical runnin<7 tests extending over a considerable period. 

 This. T understand, has been done in the case of this petrol sub- 



