326 Professor Buckland on Artesian Wells. 



in Wurtemberg, near Canstadt, where the mills were kept 

 in work during the severest cold of winter, by means of the 

 warm water from Artesian wells, which overflowed into the 

 mill-ponds, and prevented them from freezing. And at Heil- 

 broon, also, there were persons who saved the expense of 

 fuel by conducting Artesian warm water in pipes through 

 their houses and green-houses. In France, M. Hericart de 

 Thury, a distinguished engineer, and president of the Royal 

 Agricultural Society of France, has published a most interest- 

 ing history of the Artesian wells in that country, all in theo- 

 retical accordance with the wells in Wurtemberg and Eng- 

 land. Let those who doubt go to Grenelle, and see the 

 majestic column of warm water from that philosophically 

 predicted fountain, rising thirty feet above the surface, at the 

 exact temperature foretold by Arago, and learn the correct- 

 ness and value of practical deductions from geology, applied 

 to the useful purposes of life. 



The learned professor then explained the principles of 

 hydrostatic pressure that are involved in the theory of the 

 rise of water in common springs, and in Artesian and other 

 wells, which he exemplified by reference to maps and dia- 

 grams representing sections of the London basin. In this 

 and other geological basins, the position of a water-logged 

 porous bed between two beds of clay may be illustrated by a 

 tea-saucer placed within another tea-saucer, and having the 

 narrow space between them filled with sand and water ; if a 

 hole were drilled through the bottom of the upper saucer, 

 and a quill or small pipe fixed vertically in the hole, water 

 would rise in this pipe to the level at which it stands within 

 the margin of the lower saucer, its rise being caused by the 

 same hydrostatic pressure that raised the water in the well 

 on Southampton Common from the vast subterranean sheets 

 of this fluid which exist in the fissured chalk-beds of the 

 Hampshire basin, as they do also in the chalk under the basin 

 of London. The rain that falls on the uncovered chalk 

 within the area of these basins descends, by countless crevices, 

 into the lower regions of tjie chalk strata to a level, where 

 they are permanently charged with water throughout all their 

 interstices and fissures, as the water charges the interspace 



