326 



The Water Supply of London, 



[July, 



According to this table, the Chelsea company's water possessed, 

 in February last 16*2 degrees of hardness, and 100,000 lbs. of it, 

 when used for washing, destroyed or wasted 194*4 lbs. of soap; 

 whilst Loch Katrine water had only 0*3 degree of hardness, and 

 100,000 lbs. of this water destroyed only 3 6 lbs. of soap before the 

 detergent action of the latter came into play. Such is the chemical 

 history of the water at present supplied to the metropolis, and it 

 must be borne in mind that, grave as are its defects, the mode of 

 delivery of this water to consumers is still more defective. That in 

 a densely populated city, water should be delivered only once, and 

 for a few minutes, in twenty-four hours, and not at all on Sundays, 

 is a condition of things utterly incompatible with the supply of 

 wholesome and palatable water. Even if the water of Loch Katrine 

 itself were delivered in London, according to the system at present 

 adopted by the metropolitan water companies, it would infallibly 

 be rendered unfit for human consumption after twenty-four hours' 

 exposure to the vile atmosphere and sewer gases in which the water 

 cisterns of London are systematically placed. 



The fundamental defects of our present water supply may be 

 thus summed up : — 



1. Great previous sewage contamination. 



2. Liability to present sewage contamination. 



3. Great hardness. 



4. Intermittent supply. 



The waters from the sources of the Severn, and from the Cum- 

 berland lakes have not yet been submitted to the process of investi- 

 gation above indicated, and it is therefore impossible to compare 

 them in all respects with the present metropolitan supply. The 

 water of the Bala Lake, in North Wales, which may be regarded as 

 similar to that which would be supplied by Mr. Bateman's scheme, 

 was examined by the late Dr. E. D. Thomson, and the waters of the 

 Cumberland lakes have been more elaborately investigated by Pro- 

 fessor Way. From the analyses of these chemists the following 

 numbers are calculated : — 



Bala Lake 

 Hawes Water 

 Ulls water 

 Thirlmere 



Total solid 

 impurity in 

 100,000 parts. 



Hardness. 



Soap 

 destroyed. 



2-97 

 5-70 

 5-94 

 5-16 



2°-9 

 3°-0 

 2 -1 



13-2 

 34-8 

 36-0 

 25-2 



A comparison of these numbers with those given in the previous 

 tables exhibits the great superiority of the proposed waters over 

 those at present supplied to London, as regards total solid impurity 

 and soap destroying ingredients ; whilst it can scarcely be doubted 



