66 



THE CIVIL ENGINEER AND ARCHITECrS JOURNAL: 



LFebbitaby, 



surveys for the sections below Teddington, These have occupied consider- 

 able time, and have been made with great care. 



[Here the report enumerates the locks and weirs, and specifies the depths 

 upon the sills, &c. It then proceeds to speak of the deposit.] 



Thf diminished water would have the tendency to increase the growth of 

 weeds and the settlement of deposit in all the periods, but we think it would 

 not exceed a tendcncv, as the water is clear during the times of short water ; 

 at anv rate it is not a matter which we can reduce to quantity, and the 

 sameobscrv'ations as to effect will apply to the reduction of depth in thf 

 length of the periods, some of which arc, like the sills, barely sufhcient for 

 the barges, the standard summer drought of which is 3 feet 10 inches, and 

 they oiten exceed this. • , , 



The effect of the tideway below Teddington lock comes to be considered 

 separatelv. This lock when built in 1810, had 6 feet upon its lower sill at 

 low water in times of drought. The removal of London bridge and the 

 deepening of shoals in the river near London have lowered the water so that 

 there is now only 3 feet 9 inches upon the Teddington sill (a reduction of 2 

 feet 3 inches), and the reduction would he greater if the shoals between 

 London and Teddineton were removed ; for although these shoals impede the 

 passage of barges tliev assist in preventing the water over them and up to 

 Teddington from falling lower, which is one of the causes of tlieir not hav- 

 ing heen removed by vou. In this case, therefore, the river water, which 

 follows tlie descent or ebb of the tide, is valuable, both as respects getting 

 over the shoals and keeping up the water upon the Teddington lock sill. Mr. 

 Leach has calculated that the effect of abstracting 100,000,000 gallons 

 would be to lower the level of the water at the lock and for a distance 

 downwards 7 inches, which would be a real and practical evil. 



It is proper to state that the above evil is not, in our opinion, without 

 a remedy, for bv the removal of Teddington lock, and erecting a new lock 

 near Kingston, or about a mile or a mile and a half above Teddington, with 

 a sill of sufficient depth there, removing the shoals so as to enable the 

 tide to flow more freely up to the proposed lock, and deepening the river 

 up to it, the abstraction of water would be compensated for, and the 

 navigation of the Thames improved by the greater quantity of tidal water 

 •which would flow and ebb at every tide. 



By the removal of the Teddington lock to near Kingston, as above recom- 

 mended, the drains of that and the low grounds near it would empty into 

 the river below the lock, which would, it is considered, be an improvement 

 to Kingston and the low ground near it. The suggestion for the removal of 

 Teddington lock and of the shoals is not new ; all that is meant to be said is, 

 that the proposed abstraction for waterworks will increase the necessity for 

 it. It may lie observed l-.ere that the scour of the river between Teddington 

 and London is very little afiected by the sluggish current in times of short 

 water, but is chiefly duo to the influence of laud freshes, during which the 

 discharge is from four to six limes greater. Mr. Leach made the quantity 

 below Staines during the flood in 18-18, 1,600,000,000; the Henley abstrac- 

 tion of 200,000,000 would therefore still form a considerable proportion 

 (one-eighth) of the whole discharge even in limes of flood. If it be asked 

 •whether, if the above improvements, by taking down Teddington lock, were 

 made, and the whole of tl,e river water at the same time preserved, matters 

 ■would lie still better, our answer would be in the affirmative ; but it is not to 

 be lost sight of that the object of an ample supply of good water is a very 

 important one, and that if it can be shown that London is not so supplied at 

 present, but that it would be by either of the two plans under consideration, 

 the damage which the navigation would suffer would be but small if the 

 means for lessening it which we have leferred to^were adopted : and we can- 

 not suppose that the parties who were promoting the water supply would be 

 unwilling to carry into effect the measures that may appear reasonable for 

 preventing injurv to the navigation through these operations. 



The engineers of the two plans agree that the season of drought will be 

 prolonged by these works, and that the evil of such a drought will be in- 

 creased. Messrs. Gordon and Liddell propose a remedy by means of move- 

 able weirs. We think that a more simple one may he applied in your 

 district; but as the evil is agreed, we do not apprehend there can be 

 much differrnce of opinion as to the remedy. It must also be admitted that 

 by the substitution of tidal for river water in a part of the river the quality 

 of the water will be less pure than at present. 



Wc have not all referred to the numerous other new plans for supplying 

 London from other rivers and sources, although we understand that notices 

 have been given for some of them, which we were not, until very recently 

 aware of, our instructions not having specified them. Our present impres- 

 sion, however, is that none of them would furnish that abundant supply 

 •which we are disposed to consider indispensable, if a general reform, or 

 rather revolution, is to take place in the present system of water supply. As 

 to the eft'ect of these plans upon the navigation, if the water he taken from 

 the Colne or any other river that falls into the Thames, which is the great 

 drain and recipient of all the springs in the strata that incline towards it, 

 the effect is injurious in a greater cr less degree, according to the quantity 

 and the distance up the river at which the abstraction n.ay take place. 



AVe beg to conclude by stating that the Grand Junction, the Chelsea, the 

 West Middlesex, and the Lambeth Water Works, all take their water from 

 the Thames, so that the new plans would be partly a substitution and partly 

 an addition, but the present companies' supply is from places so low 

 down the river as to be comparatively harmless. This character, however. 



would not apply so fully to the Lambeth Company, when their power to 

 take 20,000,000 of gallons per day from Thames Ditton, which is above 

 Teddington, shall be carried into operation ; and it is natural to suppose 

 that although the pnseiit companies take water from the rivtr so low down 

 as to be less injurious to navigation than either of the present schemes, the 

 tendency will be to follow the example of Lambeth in going higli'.r in order 

 to silence the complaints of their customers as to the quality ot the water 

 now furnished. 



No. III.— r/(C Watford Project. 

 Tliis prnject has for its object the taking of the supply of water 

 direct from the bowels of the earth, witliout allowing the springs 

 to overflow into the ri\ers to be contaminated, or to be discharged 

 into the sea. From experiments made in the years 1810 and 

 IStl, under the direction of -Mr. Robert Stephenson, it was 

 ascertained that a well sunk in Bushev Hall IMeadows, only 3* 

 feet deep, with four 5-iuch borings to the depth of 1.30 feet, ^'Jelded 

 upwards of 1,800,000 gallons per day, which dearly proved, that 

 by more extended works, an immense siipjily might be obtained. 

 Mr. Stephenson proposed to sink wells to the depth of luO teet, 

 and lift the water to about 50 feet above the surface of the Mea- 

 dows; and tlien to convey tlie water, by means of a brick culvert, 

 driven tlirougli the hills between Edgeware and Bushey, to a held 

 on the north of Kdge«are. ^vllere a large reservoir w as to be formed 

 to receive tlie water, whence it was to be conveyed by means ot large 

 iron pipes, along the turnpike-road to a hill near A\ est-eud Lane, 

 where distributing reservoirs were to be formed on three different 

 levels (tlie Iiighest about 180 feet above Trinity high-water mark), 

 and thence the water was to be conveyed, by means ol iron mains, 

 to different i.arts of the metropolis. Tliese reservoirs w ere ot 

 sufficient elevation to supply all parts of tlie metropolis, tor 

 supplying tlie high ground about Ilampstead, an auxiliary eiigme 

 was to lift the water from the most elevated reservoir, and torce 

 it up to a higher reservoir. Bv this plan the whole of the water, 

 excepting for Hampstead, was only to be liftsd 5^) feet above 

 the level of Bushev HaU Meadows. The total length of the work, 

 the culvert, and niain pipes from the wells at Busliey to H-dge- 

 ware-road, corner of Oxford-street, was between U and !.:> miles. 

 Tliis plan, in our estimation, was more economical than the one 

 now proposed bv Air. Ilomersham. 



i\lr. Homersharn proposes to lift the water from tlie well to be 

 sunk at Bushev Hall Meadows, and convey it by iron pipes to two 

 reservoirs to be constructed at three miles distance, on Stanmore 

 Heatli, at an elevation of 390 feet above Trinity high-water the 

 water having to be lifted 200 feet above the Meadows. At btaii- 

 more tlie two reservoirs were to contain coUectnely 70 millions 

 of gallons. The water is to be tlien conveyed from these reser- 

 voirs, by iron mains, along the turnpike-roads, to another reservoir 

 (to hold 24- million gallons) to be formed at Child s-hill, near 

 Hampstead, 302 feet above Trinity high-water, and from it a large 

 main is to convey the water along the Finchley-road to Oxtord- 

 street; and thence the water is to be distributed by branch mains 

 to various parts of London. The reserx oir at Child s-hiU com- 

 mands a district at least 110 feet above the reach of any existing 

 company. Another high service reservoir is to be formed at btan- 

 more, at an elevation of 4.90 feet above frinity high-w^ater, to 

 supply Ilampstead, Elstree, Highwood-hiU, Totteridge, Harrow, 

 Staniiore, &c. At three of these places other reservoirs are to be 

 formed, making in all seven reservoirs. By distributing the reser- 

 voirs they can be supplied from the mains at different times of the 

 day and I'lisht. By these works it is proposed to supply the metro- 

 polis with eiffht millions of gallons per day for 40,tl00 houses, at 

 170 gallons daily, and leave H million gallons for wholesale con- 

 sumers. ,, , »■ », ,t 

 The cost of forming these works Mr. Homershain estimate:, at 

 340,000/., and the annual expenses at 1.5,725/., which includes 0,900/. 

 as the cost of pumping the water, and the wear and tear ot engines, 

 which will make the expense of pumping 2*. Grf. per annum per 

 house, supi.lied with 100 gallons per day, which is what we stated 

 could be done. 



From our knowledge of the experiments that were made under 

 the direction of Mr. Stephenson, we fully believe that a very large 

 supply of water, of undoubted purity, maj- be obtained from weUs 

 suiik'in Bushey HaU Meadows, which will be sufhcient for a very 

 large district of the metropolis. 



If the works could be carried out as suggested by Mr. Stephen- 

 son, and with some trivial improvements, we should have no hesi- 

 tation in pronouncing the AVatford scheme as in ev'ery respect 

 the best for the supply of the western division ot the metropo- 

 lis 



