400 THE POPULAR SCIENCE MONTHLY. 



to draw water from a depth of thirty or forty feet, because it would 

 cut off the supply due to the rains which do not sink deeper than three 

 feet ! " But the Professor had not said that " rains do not sink deeper 

 than three feet." He had, indeed, said that one intelligent manufac- 

 turer, Mr. Dickenson, had found by a rain-gauge that " except in 

 December, January, and February, rain-water rarely descends more 

 than three feet below the soil," etc. This statement apparently con- 

 vinces Mr. Green that rain-waters never get deeper into the earth than 

 three feet. But there are soils and soils.* And Professor Buckland 

 did not neglect to point out their differences. He said, "The rain 

 that falls on the uncovered chalk within the area of these basins (like 

 that of London) descends, by countless crevices, into the loioer re- 

 gions of the chalk strata,^'' etc. And even Mr. Dickenson's observa- 

 tions during many years had shown him that, in spite of the fact that 

 in the drier part of the year the rain-waters rarely sank into his soil 

 more than three feet, yet the quantity of summer water in the river 

 Colne varied with the rain in the preceding winter. He probably 

 knew, therefore, that these winter rains must be largely absorbed by 

 the sponge-like chalk formations in the neighborhood, and slowly 

 work their Avay downward many feet, to issue gradually at lower 

 points in the form of springs to feed the river in summer. 



Mr. Green quotes further from Professor Buckland's address, show- 

 ing the great value of artesian wells in Wurtemberg, and then goes 

 on : " From which quotations it appears that the Professor is in a 

 remarkable position. At Wetford" {sic) "these wells could not be 

 utilized because the river-supply of the Coin" {sic) "would be ex- 

 hausted ; but in Germany they were a new and important source of 

 supply to the rivers themselves." The Professor's position may be 

 remarkable, but it is certainly reasonable. For it is a well-known 

 fact that in some localities, that of Tours for one, as stated by Arago, 

 artesian wells may be bored to any number hitherto tried without sen- 

 sibly affecting the flow of those first sunk in the immediate neighbor- 

 hood, while in other localities every new well either diminishes the 

 flow of old wells or makes the level of the water in them sink. This 

 last is the case near London. The " American Cyclopsedia," article 

 " Artesian Wells," says : " In the vicinity of London it is observed 

 that the height to which the water rises diminishes as the number of 

 wells is increased. In 1838 the supply of water from them was esti- 

 mated at six million gallons daily, and in 1851 at nearly double the 

 amount, and the average annual fall of the height of the water is 

 about two feet." Professor Buckland had also stated that " Mr. Clut- 

 terbuck demonstrated, by a long-continued series of measurements of 

 the water in the chalk-hills of Hertfordshire, near Watford, that every 

 drop of water taken from that neighborhood would have been ab- 



* Arago said — but he apparently lived too early — " Every one knows that in many 

 places the upper ground is of sand, and that sand lets water through it like a sieve. 



