(551 PKOCEEUINGS OF SECTION H. 



than sufficient. The costs per lineal foot would he probably 7s. 6cL 

 and OS. 3d. resj)ectively — that, is, the concrete costs 27 per cent, more- 

 than the timber to do the same work. Possibly the concrete is often 

 wortli the extra money on account of its superior durability and 

 freedom from troubles due to shrinkage and warping. In very many 

 cases, however, timber will l)e preferaljle ; it requires less headroom, 

 imposes less weight on foundations, and has a second-hand value if 

 taken out of a structure. 



With the exception of arches, there is scarcely any engineerings 

 purpose to which reinforced concrete is put which cannot more 

 cheaply and strongly be served by timber. The considerations which, 

 make concrete appropriate are principally its permanency, freedom 

 fiom nuiintenance, and its fireproof qualities. In Australian waters 

 the failure of Muntz metal to protect timber from teredo has left 

 an opening for the reinforced concrete pile, and time will tell 

 whether it will come up to expectations. It remains to be seen 

 whether the cracks which, visible or not, must often exist in the 

 piles due to handling and in driving will not some day allow sea- 

 water to reach and destroy the reinforcement. If any one will cal- 

 culate the transverse strength of a conci'ete pile I think he will be 

 prepared to concede that it is exceedingly likely to be cracked in 

 handling, and perhaps also to be cracked below the level of the 

 bracings in a wharf which is subjected to severe treatment by the 

 cables of vessels attached to it. 



In my opinion concrete, plain or reinforced, is superior to all 

 other materials in one thing, and that is in arches of large span. 



3.— WATER AXD THE ENGINEER. 

 By GEORGE VtilLJAPS, C.E., Brhhane. 



Water always has been and always will be the friend, the 

 servant, and the most powerful enemy of the engineer. 



From time immemorial it has provided him with employment — 

 it has borne up his boats ; groaned under the weight of his argosies ; 

 turned his mills, and rim through his pipes and channels. At his 

 bidding it has come from distant hills to water and fertilise the 

 valleys, to give drink to forgotten cities, and to be led hither and 

 thither in the service of man. By his controlling hand it has been 

 made to defend beleaguered cities, and it has drowned or defeated 

 attacking armies. 



In later times it has toiled and sweated in his service — has 

 moved immense weights and raced at speed over land and sea. It 

 has fought and defeated fires, has purged away dirt and disease, and 

 has cleansed augean stables. 



Now and again it has turned in its wrath; wrecked his ships, 

 destroyed his lighthouses, burst his iron bands, cut great gaps in his 

 embankments, carried away his bridges, burst his I'cservoirs, silted 

 up his docks and harbours, canned pestilence and death into houses 

 and cities, mocked his sway, broken his heart and wrecked his 

 reputation. 



