58 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



f February, 



SUPPLY OF WATER TO LONDON. 



Another scheme is hniug-ht forward for supplyin;; tlie metropolis 

 with water. It is proposed to talvC the sujjply from tlie river 

 Thames, near Henley, at an elevation of 106 feet above low-water 

 mark at London-bridge, and convey it in a canal, 1!) miles in 

 length, until it reaches the Grand Junction Canal at AV'est Dray- 

 ton, wlience it will be conveyed a distance of 15 miles to Pad- 

 dington, in the bed of that and the Paddington Canal, or in a 

 separate channel alongside of those navigations. A reservoir is to 

 be formed at Paddington, 103 feet above low-water mark of the 

 Thames ; and another high-service reservoir is to be formed on 

 Primrose Hill, 190 feet above low-water, or 172 feet above high- 

 water mark, which the promoters state will be supplied hy a 

 very niin/ik hydraulic power obtained from the fall of the water tii the 

 lower parts of London. 



Tlie (piantity of water intended to be sui)plied is 100 million 

 gallons daily. 



The cost 'of the undertaking is estimated at 750,000/.; but if 

 a separate cliannel should be made for the water for the vrhole dis- 

 tance, 250,000/. is to be added to the expense — making in all a 

 million. 



This is an outline of the promoters' scheme, which appears to 

 us has not received that mature consideration it deserves lieftire it 

 is lirouglit into Parliament : in consequence, it will, we fear, break 

 down in conuuittee. Tliere cannot be a doubt that tlie source of 

 the sui)])ly is good, and that an ample quantity of water tor the 

 wants of 'London may be procured, and that there would not 

 be any very great objection to bringing the supply by a navi- 

 gable 'canal from Henley as far as Drayton, as the navigation 

 through this distance of' 19 miles would 'not be more objection- 

 able than taking the supply from the Thames at Staines, a place 

 about the same distance below Henley as West Drayton. But 

 we have a strong objection to the course of the Grand Junction 

 and Paddington Canals, as they are fed by large reservoirs of stag- 

 nant water collected during the winter months, and let down for 

 the lockage through the summer months. These reservoirs receive 

 the land drainage of a vast tract of country : one is at the head of 

 the river Brent, near Edgware-road ; another at Elstree; another 

 at Ruislip ; and one or two others between the latter place and 

 Tring; and, besides, those canals coming witliin the range of the 

 metropolis, are lial)le to be polluted by a variety of objectionable 

 matters. The size of the canal, with' an inch fall only per mile, 

 requisite to carry 100 million gallons daily, is a much larger work 

 than we anticipate the estimates will cover — when is included the 

 settling, filtering, and delivering reservoirs: for enormous as the 

 quantity is, it will not do to allow the water to pass into tlie 

 mains without undergoing the process of tiltration, as in rainy 

 seasons the river Thames is in a very turbid state. 



If the companies' mains and jiipes are to remain the same as they 

 now are, it will be requisite to lift 10 to 15 million gallons of the 

 water for the supply of London to the upper reservoir at Primrose 

 hill, or tlie water will not pass through the mains with a sufficient 

 velocity to supply the eastern parts of London, from five to seven 

 miles distance. How this quantity is to be lifted "by a very 

 simple hydraulic power," the promoters do not tell us 



Unless, indeed, half of the 100 million gallons be allowed to run 

 to waste, to raise the 10 or 15 million gallons to the upper reser- 

 voir, by an o\ershot-wheel of 30 feet diameter, by such an arrange- 

 ment one-half of the water would be discharged at an elevation 

 of only 55 feet above high-water mark, an elevation that cannot be 

 of much service in flashing the sewers ; as for the latter i)urpose, 

 the main quantity of water should be discharged at the head of the 

 sewers throughout London. The waste water might very advanta- 

 geously be used for supplying the Serpentine — much needed, and 

 which is about 10 feet above high-water mark, and also the orna- 

 mental water in the (ireen Park and St. James's Park ; but it 

 would bo discharged too low for Regent's Park, as the lake there 

 is on about the same level as the intended Paddington reservoir, 

 unless it be raised by an additional water-wheel kept for that pur- 

 pose. 



After all, the main consideration is, can so large a ([uantity as 

 100 million gallons daily be diverted from the river Thames in the 

 summer time without being detrimental to the river between Hen- 

 ley and Brentford } And can that quantity be brought to London 

 with a fall of only an inch per mile ? If this really can be done, 

 or even 50 million galliuis, then it will unquestionably he of great 

 value to the metropolis, provided the water be properly distri- 

 buted ; for this purpose it will be indispensably necessary to have 

 another reservoir at Hampstead, with a large main for supplying 

 it, in addition to the reservoirs belonging to the present water com- 



panies, so as to ensure a constant supply at all times to the top of 

 the highest house within the district to be supplied ! In such case, 

 can all this be done within the capital of one million sterling.^ 

 W^e think not ; nor for lialf as much more, particularly if the 

 water-course of the Grand Junction and Paddington Canals be 

 abandoned. 



It is very evident, as we said at first, the scheme has been hastily 

 brought forward, and assertions made that will be difhcult to sup- 

 jiort. Instead of 100 million gallons, let the promoters be content 

 with 10 million gallons daily : that sup|dy will be ample when we 

 take into consideration the present supply of the New River; — 

 and instead of trusting to "a simple hydraulic power," let them 

 calculate for steam power to lift the water up to Hampstead, which 

 would be a mure central and elevated spot to distribute it through- 

 out the metropolis. 



PORTER'S PATENT CORRUGATED IRON BEAMS. 



Mr. Porter, of the Iron-roofing Works, at the Grove, South- 

 wark, has recently taken out a patent for the employment of cor- 

 rugated iron in the construction of beams; and for the purpose of 

 testing the strength some experiments were made, of which the 

 following is an account. Two beams made on this plan were sub- 

 mitted to the test; the extreme length of each 22 feet, and sjian 

 between supports 20ft. (iin.; deptii of beam, 18 in.; weight of 

 beam, Hii^wt.; tiie top and bottom frames were of -1 inches x 

 4 inches T-iron, and the base j inch thick; the plates of corru- 

 gated iron forming the beam being of No. Iti gauge, and the bands 

 I5 inches x 5 inch thick. The two beams were placed 9 feet apart, 

 and across these were laid two large oak blocks, weighing 1 ton 

 3cwt., and supporting the further load. These blocks, or bearers 

 (the one 19 inches and the other 24 inches wide), were 4ft. Sin. 

 apart from centre to centre, and equidistant from their centres to 

 the centre of the beam, 25.i inches; upon these were laid cast-iron 

 blocks, weighing ti tons 17cwt. This weight was put on on Satur- 

 day and remained till Tuesday, without causing any deflecti(m. 

 On Tuesday, in the course of an hour-and-a-half, an additional 

 load was apjilied of 121 bundles of plate-iron, weighing 7 tons 3 cwt. 



qr. lulb., producing a deflection of -f'j.ths inch. This load was 

 allowed to remain from 1 ji.m. oil Tuesday until 10 a.m. on AVed- 

 nesday, in course of which time the deflection had increased Vsth 

 inch. Fifty-one bundles ot plate-iron, weighing 3 tons 9 cwt. 



1 qr. 2 lb., were now added, which caused a total deflection of 



1 inch bare; rested a quarter of an hour, when 32 bundles of plate- 

 iron, weighing 1 ton IS cwt. qr. 12 lb. were added, which in- 

 creased the deflection to Igincli and 1 y'j inch respectively; the 

 difference being evidently occasioned by the settling down of the 

 piers, giving a greater load to one beam. A further load, weighing 



2 tons 8 cwt. 3 qrs., brought the deflections to li? inch and l:,'incli. 

 This loading was proceeded with gradually during tliree iiours, 

 when the load was left for an liour. In the meantime a sliglit 

 noise called attention to a partial dividing of tlie bottom flange of 

 T-iron, in the beam which hitlierto appeared the least strained: 

 upon examination, it was found to liave originated in a flaw near a 

 '•shut" in the T-iron, distant 6 ft. 3 in. from tlie point of support; 

 this caused a fuither deflection of V,y inch, but the fracture did 

 not appear to increase during half-an-hour. The deflection of the 

 beams increased to 2 inches and Ij inch with an additional load 

 of 2 tons (i cwt. 2 qrs. 22 lb. load, applied gradually during three 

 quarters of an hour. After a further lapse of 10 minutes, a 

 further load of 7 cwt. caused a rapid deflection in the already- 

 weakened beam, the corrugated iron giviug way at the same time 

 to tlie strain of the rivets lougituiUnally. The beams were now 

 blocked up to prevent any accident from the sudden falling of the 

 load. The corrugated iron of tlie other beam was also found to 

 have yielded in several jilaces to the longitudinal strain of the 

 rivets, principally in tlie lower part of the beam. 



The breaking weight is, therefore, considered to be about 

 25 tons, exclusive of the weight of the beams. 



The inventor considers that his beams will not weigh more than 

 one-half, or five-eighths, of the weight of cast-iron beams to carry 

 the same load, and that they may be made for 21/. per ton. 



