1922] The Internal Combustion Engine 589 



WEEKLY EVENING MEETING, 

 Friday, May 26, 1922. 



Sir David Salomons, Bart, D.L. J.P. F.B.A.S., 



Vice-President, in the Chair. 



W. E. Daley, M.A. B.Sc. F.R.S. M.Inst.C.E. M.I.Mech.E. 



The Internal Combustion Engine: Its Influence and 

 Its Problems. 



THE INFLUENCE OF THE INTERNAL COMBUSTION ENGINE. 



To engineers the terms horse-power and horse-power hour have 

 strictly technical meanings. They can be illustrated by comparing 

 the weight and efficiency of an aircraft engine and a locomotive 

 engine. An aircraft engine can be built with about 2 \ lbs. of metal 

 per horse-power as against approximately 250 lbs. of metal per horse- 

 power in a locomotive engine. An aircraft engine requires about 

 | lbs. of fuel oil per H.P. hour as against 3 lbs. of coal per H.P. hour 

 used by the locomotive engine, in addition to which the locomotive 

 engine must carry about 3 gallons of water per H.P. hour. All 

 these, of course, are round figures. It is the extreme lightness of 

 the petrol engine in relation to its power which has made it possible 

 to develop aircraft. 



An internal combustion engine of the Diesel type is built to use 

 heavy oils, and it is the prime mover which led to the rapid develop- 

 ment of the submarine during the war. Thus the internal combus- 

 tion engine helped to sink our food ships, but at the same time 

 helped to save us by driving the agricultural tractor. Few, perhaps, 

 realise how serious was our position in 1917. Horses were required 

 for the Army and were being taken from the farms ; but the 

 agricultural tractor replaced them at the plough and thus made 

 it possible to maintain the necessary food supplies. 



Probably the greatest effect of the internal combustion engine on 

 our national fife is its influence on road transport. Standing at 

 Hyde Park Corner twenty years ago a motor car would have excited 

 notice ; standing there to-day a horse-drawn vehicle is rarely seen. 

 The internal combustion engine is displacing the horse from the 

 streets, and is even causing the railway companies grave concern. 

 The chairman of one company stated at the last half-yearly meeting 

 that the companies had lost 9 million tons of goods, and 6 million 

 passengers to the motor lorry and the motor car. This is a remark- 



