104 3Tr. John H. Balfour Broivne [March 17, 



I remember one of the Counsel in the case who was a cynic said, 

 " Ah ! Sir AVilliam, if you had been before the Royal Institution it 

 would not have worked." That is the reason I have for not repeating 

 the experiment before you to-night. 



That 20 grains of chlorine to the gallon was not a serious matter 

 was proved by the statement that Apollinaris water, of which some 

 of the members were partaking at their frugal lunch, contained 

 59 grains of chlorine to the gallon. 



It may be of some use if I say something about the sources and 

 methods of supply. There is nothing very new about water supply. 

 Even in deep wells we have been anticipated ; Joseph's Well at Cairo 

 is 297 feet deep, and some of the wells in China have gone to a 

 depth of 1500 feet. In modern times we have in some cases been 

 abandoning our well supplies. At one time almost the whole supply 

 of Liverpool was drawn from wells in the New Eed Sandstone. 

 To-day she only draws 7* 36 per cent, from wells — 36 "42 per cent. 

 from Rivington, and 56*22 per cent, from Vyrnwy. There is a well 

 at Passy, near Paris, 1923 feet deep, and it delivers 5J million 

 gallons of water a day. In South Dakota there is a well which 

 penetrates the earth's crust 725 feet and raises 11| million gallons a 

 day. In relation to the purity of such underground supplies, many 

 of them in this country are derived from the chalk, and it is 

 interesting to note the precautions which Nature has taken to purify 

 such supplies. It is found that such soils as chalk breathe air and 

 expel gases just as the human lungs do. The breathing is long- 

 drawn and irregular, and depends mainly on the barometric pressure 

 of the atmosphere. But that such breathing takes place can be 

 shown by the simple experiment of closing the folding doors over a 

 chalk well and holding a lighted candle to the bucket rope-hole, and 

 the sensitive flare will show the indraft or outdraft as the case may 

 be ; which varies, of course, in intensity according to the extent of 

 recent barometric changes. When water has to be got from under- 

 ground sources, then a well has to be sunk, adits driven, a pump 

 established, and the water raised to the clear-water tank. In 

 some cases, however. Nature not only does the purification of our 

 water by its chalk lungs, but does our pumping for us. The artesian 

 well which gets its name from Artois in France, is a well which is 

 sunk to a pervious water-bearing strata lying between two impervious 

 layers, as in diagram. In that case the water falling on the sui'face 

 and getting into the ground at will, when the well is sunk through 

 the surface impervious stratum at the points A and B, rise to the 

 surface, Nature doing the lifting for us ; and even at the point C the 

 water is within easy reach of our pumps. 



But not only have we been anticipated in the matter of wells, in 

 aqueducts we are mere imitators of our predecessors, who even under- 

 stood, it is obvious, the principle of the inverted syphon, as it is 

 called, by means of which water is carried in pipes across valleys 



