president's address — SECTION J. 191 



dies. But tlie colonies will soon learn to make capital of their 

 own ; the saving-s of an active intelligent people devoted not 

 to wars, but to ])roductive industry, will increase from year to 

 year, and a large proportion will always be devoted to public 

 works, the necessity for which grows with the poj)ulation. 



Hitherto the most pressing need in the colonies has been 

 for roads, bridges, railways, and harbour works, and we are 

 already well provided with all these ; for although the length 

 of railways bears a small proportion to the areas of the 

 different colonies, it bears a large ratio to the number of in- 

 habitants. Thus the number of people per mile of railway 

 is: — In Victoria, 518; in New South Wales, 521; in 

 Tasmania, 330 ; in New Zealand, 360 ; in Queensland, 210; 

 in South Australia, 220; in West Australia, 92. In Canada 

 it is 400 ; in the United States, 400 ; and in Great Britain, 

 1800. 



The colonies are also fairly well provided with harbours 

 and docks, and in New Zealand some think we have over- 

 done this class of work. Roads and bridges we have in great 

 abundance, and the extension of these means of communica- 

 tion must go hand in hand with the growth of population. 



We have not yet tried our hand on canal works, as, except 

 under special circumstances, railways have totally supersedefl 

 the use of canals. 



In the future one may look forward to the canalisation of 

 the long and sluggish rivers of Central Australia, which may 

 be combined Avitli great canals for irrigation and the carriage 

 of produce. 



As the population increases other engineering works become 

 indispensable, and among them sewerage and sanitary works, 

 which are often the last to be thought of, can no longer be 

 neglected. In Austi-alia it is to be hoped that engineers will 

 devote their best attention to tliis important branch of public 

 works, because in that dry climate sewerage and waterworks 

 have a double significance, — first, to cleanse the towns ; second, 

 to save the sewage to iri'igate the land. 



It is usually taken for granted that sewers have fulfilled 

 their functions when they convey away from a town all the 

 filth that can be carried by water, and it must be remembered 

 that the liquid filth is nearly ninety per cent, of all the 

 impurities that originate in a town. But if these impurities 

 are not appUed to the land there is a waste of manure, which 

 no country can long afford to lose. 



On this subject Austrahan sanitary engineers should pause 



