16 Transactions. — Miscellaneous. 



clear, into the Thames, and employs a fleet of steamers to 

 carry the sludge practically out to sea. In both cases nature 

 is left to finish the work. It is an axiom in engineering, as it 

 should be in every calling, not to fly in the face of the work- 

 ing of nature, but to assist nature and nature will assist you. 

 So, as there are means provided by which the refuse of the 

 world is turned to good account, we have only to make use of 

 them and the mysterious operations of nature will do the 

 work. The septic treatment of sewage therefore seems to 

 offer to us more prospect of dealing with the drainage of 

 towns which have not the advantage of being able to dis- 

 charge it into the open sea. Much has been already achieved 

 in this direction, but much remains to be added by experi- 

 ence. Nevertheless, I anticipate that within a very few years 

 the treatment of sewage will be as certain and successful as 

 that of any other process or manufacture. 



The utilisation of natural sources of power must always be 

 of importance, and the question seems to be now occupying a 

 good share of attention. Water-power from rivers is usually 

 the first in such schemes, and, in conjunction with long- 

 distance transmission of energy by electrical means, offers a 

 good field ; but the scope and results are more restricted than 

 are usually believed. It is very seldom that river rapids or 

 falls can be harnessed into work except at a very large cost, 

 and even where in more favourable cases power can be got in 

 hand cheaply the distance over which it must be conveyed 

 rapidly absorbs the efficiency, and it is wonderful how soon 

 the economy of water-power is overtaken and surpassed by 

 steam-power with all its low efficiency. 



The harnessing of the tides is another scheme oftener 

 talked about than practised. There is probably no power in 

 nature at once so vast, so visible, and so difficult to utilise as 

 that of the tides. There are exceptional cases where tidal 

 power has been economically used, but as yet they are very 

 few. It seems to me, however, that much more might be 

 done in this direction, and that there are places where a very 

 considerable amount of energy might be made available by 

 a judicious arrangement of floating wheels, dynamos, and 

 secondary batteries, all under automatic control. The har- 

 nessing of wave-power on the sea-coast has been less often 

 proposed, and, with the exception of bell-buoys, still more 

 seldom put in practice. It may be found, however, that there 

 are by this means greater facilities for gathering up and 

 storing energy than by the tides. There appear to be situa- 

 tions peculiarly adapted for such an installation, such as at 

 some breakwaters which have been designed by flying a good 

 deal in the face of nature. At these places I believe the wave- 

 power might be so used that it would effectually keep down 



