BY P. L. WESTON, B. SC, B.E. IX' 



sion surprise to many to learn that even in our present 

 state of knowledge power could probably be produced 

 by gas engines at Ipswich at a price which would com- 

 pare with the cost of the average water power scheme 

 with its expensive hydraulic engineering works. Water 

 power is comparatively scarce in Australia, and for that 

 reason our engineers should be fully alive to the possi- 

 bilities of the gas engine as a source of cheap power. 



In this respect I may mention that the manufactui<> 

 of calcium carbide, which is usually considered to h<i 

 commercially possible only when clieap water power is 

 available, is now being successfully carried on in New 

 South Wales with gas engines using coke as fuel. There 

 seems to be every probability of metallurgical coke being 

 produced at Ipswich in large quantities in the near fu- 

 ture, and the generation of power from the oven gases 

 would appear to be a natural sequel. When one looks 

 into the commercial use of gas and other internal com- 

 bustion engines the most noticeable feature is the rela- 

 tive scarcity of engines of large or even moderate size. 

 The cause of this is that all internal combustion engines 

 show up to best advantage when in comparatively small 

 units, say, below 200 horse power. Larger units show 

 Qo increase, either in fuel consumption or first cost per 

 brake horse power, while increase of size is accompanied 

 by greatly increased difficulty of construction and opera- 

 tion. 



This is in marked contrast to the steam engine, and 

 more especially the steam turbine, as, in both these types^ 

 of prime movers increase of size is accompanied by de- 

 crease of fuel consumption and capital cost per horse- 

 power, while difficulties of construction and operation 

 do not materially increase. As a result gas engines over 

 about 200 horse-power capacity are almost as rare as 

 steam turbines under this capacity. These intrinsic dif- 

 ferences between gas and steam engines are due solely 

 to the higher temperature of the working fluid in the gas 

 engine. In the steam plant the fuel is burnt in the boiler 

 furnaces at a temperature of, say, 1200 degrees Centi- 

 grade, and the heat transmitted . to the working fluid, 

 steam. Avhich enters the engine at, say, 200 degrees Centi- 

 grade. 



