General Notices. 4?65 



from overflowing above the weir, the following ingenious contrivance, on 

 the principle of the common ball-cock, and that of the self-acting sluice 

 invented by the late Mr. Bramah, is suggested. " There must be contrived 

 a strong leaf, suspended by proper hinges, and made buoyant, as soon as 

 the water rises to it, by means of a copper tube, air and water tight, 

 affixed to its lower edge. The tide, in ascending, will begin to raise this 

 leaf as soon as it attains a higher level than that of the wear, and will 

 thus be the means of barring itself out. The leaf, when raised quite up, 

 will be supported against the weight of water by leaning against the pillars 

 which rise from the weir and sustain the bridge above it, should such 

 bridge be thought a desirable addition to the plan. As the tide ebbs, the 

 leaf will, of course, fall gradually with it; and the waters which have been 

 accumulated meantime above the weir will discharge themselves over 

 the dam. By thus diverting the sewers from the river above Chelsea, and 

 preventing the foul tide water from rising beyond that mark, the river, for 

 miles up, might be considered as one grand reservoir of water, which, if 

 not so pure as that of the Colne, would assuredly be far purer than any 

 with which London is at present supplied." 



Mr. Ainger's plan is as follows : — The drainage on each side of the river 

 is to be received within " a wall extending along each shore, from about 

 Vauxhall Bridge to the Tower, at a distance varying between 20 ft. and 

 200 ft. from the present wharfs or banks. The places so enclosed would 

 constitute two main sewers, north and south ; and they should be arched 

 over at a height of from 3 ft. to 6 ft. above high-water mark, forming an 

 extensive and very valuable quay or wharfage, wholly reclaimed from the 

 useless, or worse than useless, part of the river; the usual width of which 

 would, in fact, be increased by the deepening of the channel, which the 

 contraction of the upper surface, and the consequent increased velocity of 

 the current, would quickly occasion." 



Of these two plans, Mr. Martin's would be much the easier to carry 

 into practice ; hut Mr. Ainger's is certainly the more complete. We agree 

 with the able editor of the Mechanics' Magazine, in thinking that " it 

 must, sooner or latter, either in its present or in a modified shape, be 

 adopted." Such works, including the sewers, and the supply of London 

 with pure water, ought to be intrusted to a general commission, or under- 

 taken by government. It is true, they might give rise to jobs, &c, in a 

 corrupt government ; but, when we make use of the word " government" 

 without explanation, we are always to be understood as meaning self- 

 government. Mr. Ainger, who is an architect, concludes the account of 

 his plan with the following words : — " Plans of improvement, even the 

 most reasonable and obvious, require to be made public many years before 

 their advantages and difficulties are fully and generally appreciated. I 

 submit this, therefore, in a somewhat immature condition, for the purpose 

 of eliciting that discussion by which, if it be worth notice, its usefulness 

 and practicability can alone be determined, and its ultimate success 

 promoted." 



A Plan for filtering the Water of the Thames, and supplying it to the 

 metropolis and its suburbs, by L. W. Wright, Esq., engineer, has been 

 communicated to the Royal Society, and is thus noticed in the Philosophical 

 Magazine for May, 1831 : — " The author, after giving extracts from the 

 report of the commissioners appointed by his late Majesty to enquire into 

 the supply of water to the metropolis, in support of the practicability of 

 affording a supply of filtered water from the Thames, adequate to the 

 demand, and within reasonable limits in point of expense, proposes his 

 plan of forming a filter under the bed of the river for each company. He 

 states that the deposit of mud on each side of the Thames does not reach 

 below the low-water mark, and that the bed of the river throughout is 



Vol. VIII. — No. 39. hh 



