172 



THE CIVIL KNGINEER AND ARCHlTECrS JOURNAL. 



r J U N E 



improve Ihe outfall through the main Hartshorn-lane sewer by a work of 

 consiJerable labour, which will need 1,300 feet of tunnelling. Upon this, 

 we cannot help observing, as we did last month, that it is really a pity to 

 see the waste of money and the inefficient measures, which are the result 

 of the present system. We then pointed out that a large sewer, belonging 

 to the Kegent'spark and Regent street commission, runs through the centre 

 of the Hestminster district ; and yet, that for the latter, distinct outfalls 

 are sought and the channels constructed, at an enormous expense. If an 

 arrangement were now entered into between the two commissions, for the 

 purpose of allowing, the sewers in the vicinity of Regent-street to commu- 

 nicate with the Regent-street sewer, a vast outlay would be saved iu re- 

 building the sewers, no doubt, by partly raising and partly lowering the 

 bottom of all the sewers on each side of Regent street, to the distance of 

 ."iUO yards. The accumulation of the filth in those sewers might be got 

 rid of, particularly if a new bottom were made to the sewers of a circular 

 shape ; in fact, this latter arrangement could be done to most of the old 

 square-built sewers. 



In the present case, Mr. Phillips canvasses the propriety of communi- 

 cating with the King's College Pond sewer; but he says not one word of 

 the Regent-street sewer, which runs through his district. The drainage of 

 Devonshire-street, which lies on the latter sewer, is therefore proposed to 

 be carried through several bends and at right angles, down to Broad-street, 

 Bloomsbury, a distance of many thousand feet— when the Regent-street 

 sewer can be entered at the bottom of Devonshire-street. We say nothing 

 as to the necessity for improving the Hartshorn-lane sewer and outfall; 

 but we do urge, so far as the streets in the neighbourhood ot the Regent- 

 street sewer are concerned, that the Westminster Commissioners should 

 have a conference with the Commissioners of Woods and Forests, and come 

 to some arrangement. 



Mr. Phillips estimates that his plan will require the rebuilding of 25,176 

 feet of sewer, at a cost of £20,140 ICs. ; but he does not dare to recom- 

 mend the immediate execution of bis plan and the disbursement of this 

 sum,— but proposes, as a first instalment, the outlay of £1,057. Suppos- 

 ing this to be one year's outlay, and that the saving of human life should 

 be in proportion to the average of Cavendish-square, and to the gradual 

 extension of the sewers,— the number of persons destroyed during the 

 gradual execution of the plan would not be much more than 1,539, or the 

 population of a good sized market-town ; whereas, by the immediate dis- 

 bursement of about £13 a-head, the destruction of so many humau beings 

 might be averted. Supposing the money borrowed at 3 per cent., for the 

 purpose of making the immediate outlay, the additional charge for this 

 would be about thirty shillings per head on the whole number of indivi- 

 duals proposed to be murdered. Perhaps the Humane Society, or some 

 other Society, might think it worth while to advance the money as a gift, 

 and thereby save so many human lives. 



The public have been greatly scandalised by the promulgation of the 

 fact, that the mortality in parts of Whitechapel and the eastern districts is 

 1 in 24 yearly ;— but we believe they were not prepared for a mortality of 

 1 in 27 in Marylebone— and that mortality, as a public officer has shown, 

 caused by the shameful state of the sewers alone. It is in the presence of 

 such facts, that Lord IMorpeth has taken on himself the responsibility of 

 withdrawing that measure of legislative relief, to which the inhabitants of 

 the metropolis have so long looked forward ; and he has thereby taken the 

 further responsibility of sanctioning a system of administration which the 

 medical profession, the engineers, and the press have justly pronounced a 

 system of wilful murder. 



After the engineering profession have so long exerted themselves for the 

 improvement of the state of the metropolis, it is quite disheartening that 

 they should be deserted by the minister of the department which professes 

 to take charge of the subject. So long as there was a prospect of a Go- 

 vernment job in emplojing military engineers to make a metropolitan sur- 

 vey, to superintend civil works, and to receive the emoluments of civilians, 

 the government were zealous enough ; but when this inducement is taken 

 away, the commissioners of sewers are allowed any reprieve they choose 

 to claim. 



If the removal of the filth of the metropolis be an important object, the 

 saving of the valuable manure which is now wasted is no less deserving of 

 consideration : but we are afraid this also is likely to meet with the fate of 

 other measures of improvement. The Metropolitan Sewage Manure Com- 

 pany have this session applied for a new act to enable them to lay down a 

 receiving sewer, which shall cut the sewers at a mean distance of 620 

 yards from the river, iuvoUiug very expensive works. To this, Mr. John 

 KartiD, the founder of the company, objects, — and proposes an alternative 



plan, for receiving the contents of the sewers near their outfall, which cer 

 tainly appears the more rational plan — and we can conceive, from such 

 evidence as we have before us, no reasnus for the company's plan. 

 620 feet would be a great distance from the river, but 620 yards seems 

 monstrous — for thereby the large intervening district is left unwrought. 



We may here observe, that we look upon the useful application of the 

 manure of towns as a great boon, which engineering knowledge will 

 confer upon the tillage of this island. From a town population of four 

 millions, and with the great body of horses employed by them, a quantity 

 of valuable manure is obtained, which cannot be reckoned at less than 

 equivalent to the production of halfa-milliftn of quarters of corn yearly, 

 or the yearly food of half-a-miUion of humau beings. When it is con- 

 sidered how the refuse of the dustyards of London is economised, it is 

 strange that the.produce of the sewers should be wasted. The old metals, 

 the broken pots and pans, called pickings, the rags, bones, cinders, small 

 coal of the dust bins, are all saleable; the produce of tlie cesspools is 

 made a lucrative branch of business, and manures are made from it in 

 London which are sent out even to the sugar plantations in the West 

 Indies — but the greater part of the manure of the metropolis is sent into 

 the Thames to pollute its waters. 



MEASURES OF FORCE AND LAWS OF MOTION. 



Sir— In your last number, you state (page 129) that — " If when a body 

 is in motion, it be acted upon by an invariable force, iu the direction of its 

 motion, the quantity by which the velocity of the body will be increased or 

 diminished (according as the force is accelerating or retardinj;,) will always 

 be the same in the same time; and is quite independent of the initial velo- 

 city which the body possessed before it was subject to the influence of the 

 force." Further — 



" This fact at once furnishes us with a convenient dynamical measure of 

 force, known by the name of the measure of accelerating force." . 

 "Thus gravity accelerates the velocity of a body falling in vacuo by 32^ 

 feet a second ; taking feet and seconds as units of space and time, the ac- 

 celerating force of gravity is represented by 32^." — This is all perfectly 

 true ; but there is considerable danger of an erroneous inference of great 

 practical importance being drawn from it, which it is well to guard against. 



Suppose a heavy body to fail from a height so as to occupy several se. 

 conds in falling ; the effects may be tabulated thus : 



Now, as the amount of acceleration communicated to the falling body by 

 gravity in any one second is precisely equal to the amount so communicated 

 in any and every other second, an unguarded reader may easily fall into 

 the error of supposing that the amount o( gravitating force expended (if I 

 may so term it) upon the fdlling body in any one second is, in like mauner, 

 precisely equal to the amount so expended iu any other second. 



In fact, not only unguarded readers, but also very able writers, appear 

 to have fallen into this error; imbodying it in the untrue doctrine, that the 

 momentum* of a moving body is as its weight (or mass) multiplied by its 

 velocity. The truth being that the momentum is as the weight multiplied 

 by the square of the velocity ; a truth of the greatest importance in ques- 

 tions concerning the effects of hammers, fly-wheels, ordnance, &c., and of 

 winds, waves, and currents of water, — the resistance of water to the pas- 

 sage of vessels, &c. 



If it be necessary to prove this truth, a mere inspection of the foregoing 

 table is enough, as respects falling bodies ; for it is therein seen that while 

 a fall of 16 feet produces the velocity of 32 feet per second, a fall of 04 feet, 

 that is four times the fall, only produces double velocity ; nine times the 



* Perlicps the real ditference may lie in our ditferently understanding the word mumen- 

 tum. Aly understanding of the term is at leust a practical oue, viz. : that it means Ihti 

 amount of power which can be com iiunicated to a body by putting it iu motion, and 

 which can^be taken back from it by stopping its motion ; this amount of power being mea- 

 sured in the manner in which the animal power, mill power, fitc, are ordinarily mea. 

 sured. 



