The Press. — London, England, 1858-07-17 00:00:00

~ f" 690 the mud•bsoks should be obliterated, either by cover ing them with water or by means of an embank ment. I think the nearest point that can be ob tained on the north side of the Thames as a point of discharge for the sewage would be at Barking. creek. It would be there carried into the river with out danger to the inhabitants of the metropolis. By Mr. TITE : I do not think deodorization would be necessary at all times of the year. lam ac quainttd with other prolesses of deodorization than by lime. I have seen deodorization by sulphuric acid, and the deodorization is complete, but it is very expensive. I have seen the sewage deodorization at Rugby, and there it is carried on by the admixture of ashes and clay, and the liquid sewage is pumped on to the land. As a commercial speculation the works at Rugby are a failure, as the sum obtained for the sewage is just sufficient to cover the expenses, and nothing is gained. There are pipes, to which a hose is attached, and the liquid is then distributed over land. Ido not think the water in the sewers could be deodorized in the sewers themselves—it would be impracticable. Neither could it be done at the mouths of the sewers, as there would he an immense amount of deposit. It would be possible to convey the sewage when deodorized away in barges ; but that would render it necessary to have numerous depots on the banks of the Thames. with tanks and steam-engines to lift the water into the tanks, while other steam engines would be required to pump the sludge into the barges. Slush could not be conveyed away to the country in pipes, as the precipitation would soon stop up the pipes. Ido not think deodo rization could be applied to the Fleet-sewer or to the mouth of the large sewer passing down King William•street, London-bridge. The ordinary sewage of London amounts to 80,000,000 gallons per annum, and it would not be possible to deodorize such a quantity by means of caissons or vessels in the river. I. see no remedy for the purpose of cleansing the banks but by the construction of an embankment and then filling up the space beyond IL I consider an iron sewer all but impracticable, as it would not bear external pressure. If the iron sewer were of a semicircular form and a flat top there would be an irregularity of pressure which I have no doubt would lead to a fracture. Any sewage that might pass Woolwich would never be injurious on its return up the river. By Mr. AKROYD : There is no deficiency at present in the scour of the river. The difficulty is because the water can never get out, continually oscillating backwards and forwards with the tide. There is a great scour in the river, and in some parts the bed of the river has been deepened four feet- If the sewage were discharged at Barking creek it would be in much the same state as it is now, but the effects would not be the same as they are now, for then it would be mixed with a larger volume of water. Some years ago water was pumped from the Thames in the middle of the stream which is now so offensive, and was fit for drinking, in consequence of the sewage being mixed in the large quantity of fresh water; and so it would be if it were discharged at Barking creek, as there the volume of water would be so great that it would deodorize the sewage. By Sir B. HALL : I consider the two works desire able for the improvement of the Thames would be intercepting sewers and an embankment, but I do not think they need both be carried on simulta neously. If there was a perfect system of intercep tion the quantity of sewage which would get into the Thames would be so small that the river would then be rendered as pure as it was twenty or thirty years ago, and under those circumstances I. do not think it would be absolutely necessary to carry on with the system of interception simultaneously a plan of Thames embankment. A large population would be benefited by the construction of the high level sewer, but it would be essential that the low level sewer should be carried on simultaneously with it, so as altogether to remove and prevent the sewage from falling into the Thames. If a low level sewer was constructed, a great many of the existing sewers draining into the Thames would require to be reversed so as to drain into the intercepting sewer, instead of into the river. If no embankment were made, and we had discharged the sewage from the high and low level sewers, a difficulty would arise on the north side, as it would be attended with consider able risk to construct a large sewer through the streets as to the security of the houses; but such would not arise if there was an embankment. On the south side there would not be any great difficulty, as the sewers there were many of them without any fall whatever. By the Hon. PERCY JOCELYN There would be no difficulty in the construction of tramways from the wharfs to the river on the embankment. If there was to be an embankment it would not alter the level of the water. The level of the water would be regulated by the height of it at the Nore at high water. By Lord PALM ERSTON The passage of the sewage downwards is ouly half-a-►vile in twenty-four hours- Therefore, if all the river could be stopped for 6kiMlimmi•••=u THE PRESS, JULY 17, 1858. twenty-four hours, the sewage could only get half-a mile from London. The sewage left on the banks in winter would not be offensive, except it was subjected to the sun's rays, and then there is a steam arising from it. Ido not think iron tunnels would answer unless they were of great strength. The bottom of an iron tunnel would not be affected either by the action of the sewage or hard substances which might get into it materially. If the detritus of streets were brought down into the iron tunnel by means of storm water, its action might slightly brighten the inside of the pipe, but there would be no chemical action upon it. In the case of the application of the sewage manure at Rugby it had the effect of fertilizing the land, but it was in the case of Rugby an exceptional case, as the substratum was very open, and soaked into the apertures, but, applied to ordinary land, it would have no such effects. Sewage is applied to the purpses of irrigation in the neighbourhood of Edinburgh, and with success. Land there will let for 30/, per acre, but it should be remarked that a Scotch acre is larger than an English one. in other places the sewage manure was not worth carrying to a distance, but the deodorization of sewage would greatly improve the river. By Mr. ROBERT STEPHENSON : I know of DO other means of improving the river but by a system of in terception. if the sewage was conveyed to Barking creek it would be there rendered innoxious by being mixed with five or six times the quantity of water as it is now mixed with in London. Besides, the offen sive odour of passing through London would altogether be avoided. More than fif teen or sixteen square miles on the south side of the Thames are now not drained more than eight hours a day. I propose three intercepting sewers on the north side, and I do not think that if two of them were made now that it would restore the Thames to what it was 100 years ago in consequence of the alteration which has taken place in compelling persons to connect their waterclosets with the sewers. My plan for a Thames embankment is not necessarily connected with a system of intercepting sewers. If the inter cepting sewers were made to Barking on one side of the river and Crossness ou the other, they could at any time be made available if it should be desired to extend these sewers to the Nore. Id 3 not agree with the proposition for deodorizing the sewage as a permanent or efficient means of getting rid of it, and I believe it can only be - effectually dealt with by a system of interception. By Lord JOHN MANNERS : If the sewage was dis. charged below Woolwich at high water it would never return to Woolwich as sewage. I have arrived at that conclusion from personal observation and also from experiments with the float, and it leads to the conclusion that the sewage will never rise higher than the point from which it is discharged, besides being subject to the action of the fresh water from the upland districts. If the sewage is discharged at high water it will not come so high up the next tide, the next otter not so high RS that, and so it will be brought backwards and forwards, until at last it gets into the sea. Taking Woolwich as the starting point, I am sure that the sewage will not come back to it in an offensive state. Having mixed with the sea water it will come back in a perfectly deodorized state. Off Greenwich the offensive state of the liver is at its maximum. Myself, in conjunction with Mr. Bidder and Mr. Bazalgette, have agreed to a plan in which we propose to aischarge the contents of a number of sewers, the mouths of them being in very deep water, and that there shall not be less than twenty feet of river water above them. As a large portion of the sewage will he discharged from points higher than Woolwich, the sewers will discharge a much larger quantity in a shorter time than they do at present. I have made a calculation as to the sewage that will flow into the river when a change is made. The total amount will be the same, but it will flow into the river in a shorter period of time. lam of opinion that if our plan of interception of the sewers is adopted, some plan of deodorization should be com bined with it, to be used at certain periods of the year. It will not cost the same, whether the opera tion of deodorization is continued for six months or twelve, as we should have to make reservoirs to con tain the sewage during certain periods of the tide, and no outlay would be required beyond that for the erection of a steam-engine and other apparatus for the purposes of deodorization. The saving would be the wages of the persons employed and the carting or sending the sewage away. On the whole, lam not in favour of deodorization except in particular cases. I consider it would take seven years to carry out a complete plan of intercepting drainage, but great relief could he afforded to those on both the north and south sides of the river in twelve, or at any rate in eighteen, months from the present time. I would recommend the deodorization of the sewers by lime in hot weather. I would anticipate an event of this kind, rather than wait until it has occured. I would begin the use of lime in May, and I would continue it until October. I would pour milk of lime into the sewers about 400 yards from the outlet, and would keep it constantly mixed with the sewage. There are other materials for deodorization, but are more expensive than lime. I am aware of expense of the lime which i 3 at present used in sewers ; it is about 15')1. per diem. I would con' that process for four months in the year at the 1 I know of no other mode that is less expensi better. Mr. Wickstecd had used lime successfui the deodorization of the sewage of Leicester. TI is a great deal of offensive matter from manufactories in that town. . _ — By Sir J. SHELLEY: I would begin the drainage with the high level sewer first on the north side. The Hackney district, which now drains into the Hackney_ brook sewer, is in a most deplorable state, and that would be relieved by the construction of a high level sewer. By the CHAIRMAN : There is a perfect concurrence on the part of the n.ost eminent engineers of the present day as to the propriety of the plan now pro. posed. At ten minutes past four o'clock the committee adjourned. This committee met again on Thursday, Mr. N. Kendall in the chair. _ Mr. BAZALGETTE, engineer to the Metropolitan Board of Works, was recalled and examined by the chairman. He said :—I have made experiments since I was last here in the burning of gases. 1 made arrangements after I left the committee on thu former day for examining Mr. Gurney's plan. On Saturday we examined the sewers, having previously cut off all communication with Mr. Gurney's furnace, and in many of the sewers we found a downward current towards Buckingham Palace, instead of towards the furnace. Sometime afterwards we con. nected the sewer with the furnace, and without the use of the steam, yet we found a current of 411 feet per minute, which was afterwards increased to 462 feet per minute. We then examined the sewer, and then found that there was a flap in the sewer, cutting off the communication of one part of the sewer to the other, so that it was impossible the air could be drawn into the ventilators near Buckingham Palace. As soon as the flap was raised, the accumulated gases caused an explosion in the clock tower. The chimney is very defective, and its communication with the sewers very circuitous. If 1,800 miles of sewers were to be ventilated, it would require eight chaldrons of coke per day ; but this large quantity might be attributed to causes connected with the experiments. Making allowance for that, I have put down the coke consumed per day at four chaldrons, and for the 1,500 miles of sewers I calculated that it would require 237 furnaces. The cost for coke for each would be 8071. per annum, and, taking the estimate of four chaldrons of coke for each, would cost 201,837/. per annum for coke alone. Each of the furnaces would cost 20,00(11. to build. I have made no estimate of what the total scheme would cost, the outlay for coke appearing to me to be so enormous. I do not think it possible to carry out the scheme with any satisfactory result. By Mr. AKROYD : I am the engineer for carrying out a plan of interception by the Board of Works. I estimated the cost of an intercepting sewer to take the sewage to Barking•creek at 2,400,0001. The interest on that outlay would be 80,000/., exclusive of 40,0001. for deodorization purposes. Mr. GOLDSWORTHY GURNEY was recalled, and said that the experiments had been carried on under most unfavourable circumstances, nor had they had a fair trial. The whole sewage of the metropolis would only give off 500,000 cubic feat of gas per day. Three towers like the clock tower would burn the gases from all the sewers in the metropolis. By 111 r. TITE I cons►der the experiments of Mr. Bazalgette were unfairly conducted, and he seemed to be in the interest of other parties. Sir B. HALL : As the lion. member has come to a conclusion, I must say I have come to tho very opposite one. Having given every attention to your explanations, I have come to the conclusion that your experiments have been wholly unsatisfactory. Therefore I ask you, do you wish any further evidence as to testing the experiments? Mr. WICKSTEED, examined by the CHAIRMAN: I have given a good deal of attention to the subject of deodorization of sewage at Leicester. It was the general sewage of the town. I established the works at Leicester, under the Corporation of Leicester, and constructed the sewers at such an inclination as to leave no deposit in the sewers. These sewers were connected with the works, into which the sewage was pumped up by steam-engines into a reservoir. In its passage to the reservoir, a stream of lin.e•water was pumped into it, and this caused a precipitation of the organic matter, and destroyed the smell. (The witness then, at some length, proceeded to explain the process of converting the sewage into manure, which was quite of a technical nature.) I believe the principle of deodorization could be suc cessfully applied to the sewage of the metropolis, by works established in the outskirts of London. (This witness, following the example of several others, spoke in so low a tone as to be almost inaudible to all more than about three feet from the shorthand 2, but they vare of the ,sed in the d continue the least. :pensive or fessfully in 3r. T hero lufactories 3 drainage I side. The ► Hackney_ e, and that high level mcurrence ers of the a now pro. committee ay, Mr. N. etropolitan ned by the sperimants f gases. 1 ttee on thu plan. On previously y's furnace, downward instead of rds we con- w►thout the of 411 feet ased to 462 sewer, and ver, cutting he sewer to fir could be am Palace. dated gases 3wer. The munication )0 miles of ;quire eight .ge quantity w►th the , I have put chaldrolia, aced that it oke for each he estimate Ist 201,637/. he 1 urnaces no estimate outlay for I do not ►e with any 'or carrying of Works. wer to take )00f. The exclusive of