BY P. L. WESTON, B.SC, B.E. XV. 



minous coal, wood, etc., which have been previously found 

 difficult to gasify in the ordinary form of updraught pro- 

 ducer without including tarry vapours which affect the 

 running of the engine. 



A number of different types of producer have been 

 designed to obviate this difficulty, and it is perhaps 

 worthy of special mention, that one of the most pro- 

 mising designs originated in New Zealand, and is coming 

 into local use. This development, if it proves as success- 

 ful as present indications promise, will still further popu- 

 larise the suction gas plant, especially in fairly moderate 

 sizes where the cost of fuel begins to be a considerable 

 item. The influence of such a cheap and convenient 

 source of power for comparatively small installations is 

 no mean factor in the development of every country, and 

 more especially in a comparatively young and sparsely 

 populated country like Australia. The small manufac- 

 turing concern, the butter factory, the irrigation plant 

 of the farmer, the isolated electric light installation are 

 familiar instances of its ready apj^lication. In many 

 other countries the Diesel oil engine is a close competitor 

 of the suction gas plant for such work, but locally the 

 comparatively high cost of oil, and the uncertainty of 

 supply, have put it at a disadvantage. It is in the sphere 

 of portable work of all kinds, however, that the internal 

 combustion engine has made its influence most felt. It 

 is almost unnecessar}^ to mention its use for motor 

 car, motor boat, and aeroplane work. So great has been 

 the demand for engines for these purposes that already 

 a very high degree of excellence has been attained in 

 the design and manufacture of petrol engines of these 

 types. 



A critical examination of, say, a modern aeroplane 

 or high-class automobile engine discloses a truly cour- 

 ageous piece of machinery, which for lightness of con- 

 struction in relation to output would have been con- 

 sidered mechanically impossible a few years ago. The 

 demand for materials of the highest possible strength 

 has led the metallurgist to produce various alloys of iron 

 and other metals, usually termed alloy steel, which pos- 

 sess extraordinary strength and toughness. For in- 



