74 



NA TURE 



{May 16, 1878 



Bateman's project of taking Thirlmere for the additional 

 requirements of Manchester and the towns on the line 

 of aqueduct. The rainfall is stated to be 98 inches per 

 annum, which it is calculated will afford a supply of 64 

 million gallons a day, of which more than 13^ will be 

 given back to the streams as compensation. The route 

 to Manchester is 102 miles in length, the Lune will be 

 crossed fire miles above Lancaster, the Ribble five miles 

 above Preston by pipes capable of conveying in the first 

 instance, 10 million gallons a day ; but the covered 

 aqueduct from Thirlmere to the service reservoir at 

 Bolton, will be large enough to convey 50 million gallons 

 per day. The estimated cost of the first instalment of 

 water will be if millions. 



At present Manchester is supplied by a series of 

 reservoirs collecting the rainfall of 18,000 acres of lower 

 carboniferous rocks, consisting of permeable sandstones 

 and impermeable beds of shale, which latter support the 

 water absorbed by the pervious overlying strata. This 

 water is not conveyed away down the dip planes of the 

 strata, into other water-sheds, but is returned to the 

 surface of the basin in which it falls ; so that out of 45 1 

 inches of rainfall no less than 33 have been collected in 

 the reservoirs. The supply from these Longdendale 

 reservoirs will very nearly reach 25 million gallons daily, 

 or 25 gallons per head of the existing population of 

 Manchester and district, without any additional supply 

 from Thirlmere. 



In the Liverpool Gravitation Waterworks area, in the 

 Rivington district, the geological conditions are similar ; 

 the drainage area is 10,000 acres, the average rainfall is 

 46 inches, and the mean from 1861 to 1865, was 44 inches, 

 of which 33^ were collected, leaving 10^ inches for eva- 

 poration and absorption. Part of the Liverpool supply is 

 derived from wells in the New Red Sandstone, the Green 

 Lane Well having yielded no less than 2)k million gallons 

 per day. 



The New Red series occupies an area in England of 

 7,431 square miles, absorbing on an average 10 inches of 

 rain annually, or 400,000 gallons per day, for each square 

 mile of surface, and affords over nearly the whole of the 

 district an abundant supply of water which is described 

 by the Rivers' Pollution Commissioners as " almost in- 

 variably clear, sparkling, and palatable, and amongst the 

 best and most wholesome waters for domestic supply in 

 Great Britain." 



The great importance of the New Red Sandstone as a 

 source of pure water makes its southern and eastern 

 range under the newer formations a matter of some 

 interest. At Scarle, near Lincoln, in a boring that attained 

 a depth of 2,030 feet and reached carboniferous strata, 

 it was passed through and was 786 feet thick, affording 

 a very plentiful spring of water, which rose six feet above 

 the surface. 



Southwards the New Red series rapidly thins, but the 

 thin end of the wedge is present at Burford, west of 

 Oxford, where true coal measures have been reached 

 beneath them ; and still further south, at Crossness, the 

 new boring of the Metropolitan Board of Works, after 

 penetrating the Gault with its phosphatic basement bed, 

 with the characteristic Ammonites interruptus, traversed 

 certain red beds which are possibly referable to the Trias, 

 and which would probably, if bored through, be found to 

 be not less than 178 feet thick. 



The Commissioners comment very favourably on the 

 character of the waters derived from the Oolites, the 

 volume of which is immense, the "Seven Wells," forming 

 the head waters of the Churn, yielding two million gallons 

 daily; the Syreford spring four millions, issuing at the 

 base of the Inferior Oolite ; other powerful springs in the 

 Fuller's earth yield twelve and even twenty million gallons 

 per day, which might be made available for the supply of 

 Oxford, and other towns on the Thames, as Prof. Prest- 

 wich has ably pointed out in his "Oxford Water Supply." 



The Thames, above this city at Wolvercot, has an average 

 daily summer flow of seventy-three million gallons, in- 

 creasing to 742 million gallons in winter floods, which 

 proves the quickness with which the Oolitic waters are 

 given off, the amount absorbed by the rock bemg probably 

 nearly all returned to the Thames basin, its onward pro- 

 gress down the dip planes of the strata towards London 

 being stopped by lines of fault. Three million gallons of 

 water are pumped from these oolites by the Thames and 

 Severn Canal Company, and most of this water finds its 

 way into the watershed of the latter river. 



The Lower Greensandand Upper Greensand both yield 

 large supplies of pure water to a large district in the 

 south-east of England ; they were proved in the deep 

 boring at Meux's brewery, to overlie the true Devonian,' 

 which rises there and form the old palaeozoic ridge under 

 the London basin. At the new boring at Crossness the 

 lower greensand was absent, but the gault is so constantly 

 unconformable to the lower cretaceous strata, and rests 

 in the south-west of England on various members of the 

 oolitic and liassic strata, that its occurrence on the red 

 rocks of probably triassic age at Crossness is not specially 

 remarkable, but would merely indicate more extensive 

 denudation of the older secondary rocks there, than at 

 Meux's brewery. This, should Mr. Godwin Austen's 

 view of the possible continuation in that area of the 

 Belgium and South Wales coal-field be correct, would 

 have the effect of shortening the vertical distance to the 

 coal-measures under the Thames basin. Be this as it 

 may, both from the scientific and economic questions 

 involved, it is a matter of considerable importance that 

 the Crossness boring should be continued, and the nature 

 of the underlying rock cleared up. 



In the metropolis, Col. Bolton reports that in the month 

 of June, 1877, the average daily quantity of water sup- 

 plied by eight companies was 132J million gallons to 

 3,796,000 people, living in over half a million houses, or 

 a little less than thirty-five gallons per head during that 

 summer month. The average daily quantity required 

 is 125 million gallons, according to Mr. Bramwell, 

 who proposes that London should receive an additional 

 supply derived from wells drawing their supplies from 

 the deep springs of the chalk, which he calculates would 

 easily yield sixteen to thirty million gallons per day, which 

 he would store in four reservoirs, north and south of 

 London, at an elevation of 400 feet above ordnance 

 datum, from which he proposes to give a separate supply 

 for potable and fire-extinguishing purposes, at an esti- 

 mated cost of 5^ millions. 



Prof. Prestwich has pointed out that the first settle- 

 ment of the London area was on the water-bearing 

 gravel beds, the suburbs extending in the direction of 

 these gravels, and that all extension stopped short at the 

 outcrop of the London clay; but so soon as water 

 companies introduced a supply of water derived from 

 other areas, the northern side of London was built over. 

 In Lancashire the middle glacial sands and gravels have 

 taken the place of the gravels of the London area, and 

 every exposure of sand rising through the boulder clay, 

 marks the site of an ancient town or village, as Preston, 

 Lancaster, Kirkham, Euxton, Leyland, Wigan, and 

 Chorley, and numerous others. 



London received its first systematic water supply in 

 1 58 1 direct from the Thames, pumped by a water wheel 

 placed in one of the arches of London Bridge by Peter 

 Morrys, an ingenious Dutchman. This continued to 

 afford a supply for two hundred years, and with the New 

 River, brought by Sir Hugh Myddelton in 1613, from the 

 chalk springs of Herts, satisfied the requirements of the 

 metropolis up to 1723, when the Chelsea Waterworks 

 were established, followed by the Lambeth in 1785, the 

 West Middlesex in 1806, and the Grand Junction in 

 1 820, all taking their supplies from the Thames. Iron 



' Determined from the fossils by Mr. Etheridge, F.R.S. 



