1867.] 



On the future Water-supply of London. 



55 



scale ; and in this respect the following table will enable the reader 

 to judge for himself: — 



Comparative Statement of Quality of the Waters supplied to Glasgow, 

 Manchester, and the Metropolis from 1856 to 1865. 



Locality. 



Glasgow — (Loch Katrine) .... 



Mamchbstkh— (Moors of Millstone 



Grit) 



London— Grand Junction (Thames) 

 West Middlesex (Thames) 



Chelsea (Thames) . . . 



Southwark and Vauxhall 

 (Thames) .... 



Lambeth (Thames) . . . 



New River 



Last London 



Kent 



Mineral 



Impurity. 

 Grs. per gallon. 



1-17 



4 



3 rax 

 Min. 

 Max 

 Min. 

 Max 

 Min. 

 Max. 

 Min. 

 Max 

 Min. 

 Max, 

 Min. 

 Max. 

 Min. 

 Max, 

 Min. 



66 



22-59 

 17-15 



21-20 

 16-62 



22-79 

 17-11 



21-19 

 17-81 

 . 22-40 

 17 75 



21-88 

 16-70 

 . 24-80 

 17-99 



27-70 

 24-60 



Organic Impurity. 

 Grs. per gallon. 



0-90 



0-75; 



Max. 1-38 

 Min. 0-68 

 Max. 2-48 

 Min. 0-70 

 Max. 1-42 

 Min. 0-84 

 Max. 1-37 

 Min. 0-98 

 Max. 2-80 

 Min. 1-01 

 Max. 2-52 

 Min. 0-45 

 Max. 2-80 

 Min. 0-63 

 Max. 1-61 to 

 Min. 1-37 



Hardness. 



0-8 



2-25 

 C Max. 14-87 

 iMin. 12-67 

 { Max. 14-40 

 \ Min. 12-18 

 j Max. 13-80 

 t Min. 12-67 

 ) Max. 13-59 

 IMin. 12-46 

 ) Max. 13-00 (nearly) 

 I Min. 13-16 

 i Max. 13-45 

 \ Min. 12-46 

 ( Max. 15-50 (nearly) 

 (Min. 13-30 

 (Max. 17-71 

 iMin. 11-36 



In reference to the above table, it is right to state that there 

 are considerable variations in the ingredients, depending on the 

 season of the year and the amount of rain. Most of the minimum 

 quantities were obtained in September, 1865, after a dry season. 

 The analysis of the Loch Katrine and Manchester Waters have 

 been supplied to us from a private source. 



It may be assumed that there are only two districts in Britain 

 available for the supply of London by gravitation, namely, North 

 Wales and the Lake Country. Mr. Bateman's scheme applies to 

 the former ; Messrs. Hemans and Hassard to the latter. In both 

 of these districts the rainfall is abundant, and the elevation at which 

 it is discharged admits of conveyance from the sources to the points 

 of delivery without the aid of machinery ; an essential element in 

 a project of such magnitude. 



Mr. Bateman starts with the principle that no scheme is worthy 

 of attention which would bring less than 200,000,000 gallons of 

 water per day. He proposes, therefore, to take the head waters 

 of the river Severn, consisting principally of the streams called the 

 Wyrnwy, the Banw, the Tarannon, and the Ceryst, which rise on 

 the eastern flanks of Aran Mowddy, Dinas Mowddy, and Plin- 

 limmon, draining an area of 130,572 acres, over which he assumes 

 a minimum rainfall of 36 inches per annum. This estimate is 

 obtained rather by the analogy of the physical features and geo- 

 graphical position of this district with that of the Cumberland 

 lakes, where the rainfall has been determined by Dr. Miller, from 



