SUPPLY OF WATER. 



less than 100 million gallons daily, which gives 

 206 gallons per house (including manufactories), 

 or 26 gallons to each person. 



There is great diversity of opinion among both 

 practical and scientific men as to what is really a 

 sufficient yet not extravagant amount of water to 

 be provided for each individual per day, many 

 advocating the principle of unlimited quantity and 

 unrestrained waste, as tending to increase the 

 prosperity of towns, and improve their sanitary 

 condition. A continual stream of fresh water 

 pouring down the drains is, in their opinion, 

 an advantage, owing to the absorbing power 

 of the water, which is supposed to oxidise the 

 gases in the sewers, and thereby to act as a 

 deodoriser and disinfectant. Others, again, of 

 equally high professional standing, declare that 

 every drop of water sent into the drains unneces- 

 sarily is nothing but sheer waste, and see no 

 possible advantage in the continual contributions 

 to the sewers, which invariably accompany the 

 use of insufficient internal house apparatus. In 

 short, the one party argue that 50 or 60 gallons 

 per head is not a drop too much, while the others 

 declare that whatever exceeds 12 or 1 8 gallons is 

 unnecessary extravagance. Probably something 

 between the two, or from 25 to 30 gallons per head, 

 may be assumed as the proper amount As 

 adverse to the side of those who advocate an un- 

 limited quantity, the fact may be noted, that in 

 places where the supply is derived from pumping- 

 engines, and where, ^consequently, every gallon 

 pumped up, and then let run to waste, is repre- 

 sented by so much coal, and therefore by so much 

 money thrown away, one never hears of indis- 

 criminate waste being advocated. 



In order to prevent waste, numerous contriv- 

 ances have been adopted to a great extent in j 

 many English towns. One great source of waste 

 arises from the ignorance of many people in sup- 

 posing that the purity and sweetness of the drains 

 is promoted by keeping the handle of the water- 

 closet propped up so as to cause a constant flow 

 of water through the pipe. Various contrivances 

 have been devised, with a view to prevent this 

 practice being followed, and also great improve- 

 ments have been effected on the ball-cocks of 

 cisterns, which, when out of repair, are very 

 frequent sources of waste. 



Artesian Wells so called from Artois, a pro- 

 vince in the north of France, where, it appears, 

 the greatest attention has been paid to the dis- ! 

 covery of subterranean springs are distinguished 

 from common wells by the circumstance of their 

 waters rising above the surface, often to a con- 

 siderable height, and with considerable violence. 

 This fact, that water will rise spontaneously to and 

 above the surface, in certain localities, when bores 

 of various depths are made into the earth, seems 

 to have been long known to mankind. An Alex- 

 andrian writer of the sixth century narrates, that 

 'when wells are sunk in the oasis of the desert, 

 to a depth varying from 100 to 500 ells, water 

 springs from the orifices, so as to form rivers, of 

 which the farmers avail themselves to irrigate 

 their fields.' In China, also, and in European 

 countries, there are proofs of wells of this nature 

 having been early formed. 



Artesian wells are common on the continent, 

 particularly in Austria and in France. That of 

 Crenelle, near Paris, is one of the most famous and 



gigantic, the borings being carried through ter- 

 tiary and chalk strata to a depth of 1798 feet, or 

 one-third of an English mile. The bore is 20 

 inches in diameter at the orifice, but is contracted 

 by stages, till at the bottom it is only 7 inches. 

 Ine bore is lined with iron tubing; and the cur- 

 rent, which discharges between 500 and 600 

 gallons per minute, rises to a height of 30 or 40 

 feet above the surface. The water has a constant 

 temperature of 81.7. The well, finished between 

 1833 and 1 844, cost 303,000 francs. In Austria 

 there are many artesian wells : one recently con- 

 structed at Pesth is some 3500 feet deep. Britain 

 also has its share of deep wells of this kind. 

 In many wells formed on the Artesian principle 

 of penetrating through an impervious stratum to 

 the water-bearing stratum of sand or chalk below 

 the water rises only partially up the shaft or bor- 

 ing, and not quite to the surface. This is the case 

 with the wells of London that are sunk through 

 the stratum known as the London clay. The level 

 in these wells is annually sinking, shewing that 

 this source of supply is already drawn upon to the 

 full. 



The geological and hydrostatic principles upon 

 which the forcible discharge of Artesian fountains 

 depends, are sufficiently obvious. The explanation 

 will be more evident by a reference to the accom- 

 panying figure, which may be considered as a 

 diagrammatic section of the London basin. There 

 is here a number of porous beds, b, b, composing 



Fig. 4. Section of the London Basin. 



the cretaceous measures, resting on the impervious 

 gault, aa, and these, again, are covered by the 

 equally impervious series of the London clay, cc, 

 which form the strata on the surface, and extend 

 to a considerable depth. The edges of the chalk- 

 beds are largely exposed in the higher grounds 

 around London ; the water falling on the whole 

 area of these exposed edges, sinks into the more 

 or less porous cretaceous beds, and would, in 

 course of time, by continued accessions, fill up the 

 basin, were it not prevented by the clay above. 

 By driving a bore, </, through this superior bed, 

 the inferior water-logged strata are reached, and 

 the subterranean water rises to the surface, and 

 flows continuously, by means of hydrostatic pres- 

 sure. 



Many such wells exist in London and its 

 vicinity ; those which form the ornamental foun- 

 tains in Trafalgar Square descend into the upper 

 chalk to a depth of 393 feet. Depending upon 

 these principles, no Artesian well should be 

 attempted without consulting the geologist or 

 mining-engineer. A deflection of the strata, the 

 occurrence of a dike, or some such phenomena, 

 which the geologist alone can interpret, may 

 render abortive years of labour. 



Artesian wells are generally formed by boring, 

 which is performed in much the same way as a 



