.lO Mr. Dickinson [Feb. 23, 



compare with the most perfect spring water, which reservoir, or head 

 of distribution, would be 120 feet perpendicular above the datum 

 line of the Ordnance Survey, made at the suggestion of the Board of 

 Health.* The Ordnance map of London, the fruit of that survey, 

 on the scale of 12 inches to the mile, with the elevation of every 

 part of the metropolis stated upon it, was exhibited, which embraced 

 also the reservoir ; and, by means of a line of uniform level traced 

 upon the map, it was made apparent how very large a portion of 

 London could be supplied by gravitation, at high-service level, over 

 and above the whole of Westminster, Belgravia, Knightsbridge, 

 Brompton, Chelsea, Fulham, and Kensington. Mr. Dickinson, 

 having had a great deal of experience in works of this nature, was 

 satisfied that the cost of delivering this quantity of water at Killjurn, 

 purified and filtered, (presuming money to be obtainable at 4 per cent, 

 per annum,) would not (according to Mr. Thom's mode of estimate) 

 exceed three farthings per thousand gallons, including the very heavy 

 item of compensation to mill-owners ; and that the whole cost of 

 distribution would not exceed threepence per thousand gallons, 

 which, as proved in the evidence of Mr. Hawksley, was the rate 

 of charge for the water supply at Nottingham. 



Some of the water taken out of the river Colne, at Harefield, 

 was produced at the meeting and much approved. With reference 

 to the liability of the Colne being rendered turbid at the time 

 of floods, (for at other times it is perfectly clear,) he quoted the 

 following evidence of Mr. Hawksley on the subject of running 

 water purifying itself, — " I can give a very extraordinary instance of 

 " that, as occurring at Nottingham. At Nottingham the supply is 

 " taken from the river Trent. Upon the tributaries of the river 

 " Trent are situated the towns of Leicester, Loughborough, Derby, 

 " Belton, and the whole of the Potteries. The water leaves those 

 " towns frequently in an exceedingly black noisome state, but the 

 " water of the river Trent is, nevertheless, exceedingly beautiful 

 " and pellucid ; in fact, at Trent Bridge, near Nottingham, it is as 

 " clear as crystal ; organic matter is not discoverable in it, except 

 " in the degree in which it is discoverable in all river water." 



The speaker concluded by stating that he had taken particular 

 notice of the amount of water expended in his own house and 

 stables, (in Upper Brook Street,) and it led him to the conviction 

 that the whole of the large and populous district, before referred to, 

 southward of, and including Piccadilly, might be supplied by this 

 application of the gravitation system at one-fourth the scale of 

 the present rate of charge ; but with the proviso, that water for 

 the streets and for public purposes, should be paid for out of the 

 parish rates as at present. [J. D.] 



* This quantity is almost exactly double that of the New River, the total 

 supply of which is stated by Mr. Mylne, the engineer of that Company, in 

 his evidence before the Parliamentary Committee of Inquiry, respecting the 

 water-supply of liondon, Qu. 8073, to be 11,872,000 gallons per diem. 



