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THE WORLD- 



Much light has been thrown upon the theory of springs by the 

 boring of what are called "Artesian Wells," so called from hav* 

 ing been first made at Artois in France ; they are made by boring 

 the earth with a large augur, three or four inches in diameter, if 

 a hard rock is met with, it is triturated with an iron rod, and the 

 fragments are then easily removed ; as the boring proceeds, tubes 

 are introduced to prevent the sides from caving, and also the 

 spreading of the water through the soil. In this manner a well 

 was bored for Holt's Hotel, in the city of New York ; 126 feet of 

 stratified sands, clay, and river mud, were first penetrated before 

 reaching the gneiss rock which underlies the island, 500 feet of 

 'this rock was subsequently bored through, and an abundant sup- 

 ply of good water obtained. When a vein of water is struck, 

 it often rushes up with great force, rising several feet above the 

 surface, affording a constant supply of water. Borings have been 

 made in France to a depth of 1200 and even 1500 feel. Occa- 

 sional failure is experienced in boring, sometimes on account of 

 the geological structure of the country, and often from the exis- 

 tence of subterranean outlets for the water. The following dia- 

 gram is from Mr. Lyell, and will illustrate the principle of the 



Artesian wells. Suppose a a, to be a porous stratum lying upon 

 an impervious bed of clays and marls, d; and covered by another 

 mass of impenetrable rock e. Suppose now that at some point 

 as at b, an opening be made which gives a free passage upward 

 to the water confined at a a, at so low a level as to be subjected 

 to the pressure of a considerable column of water, which we may 

 suppose collected at /, in a more elevated district. The water 

 will rush out at 4, and rise to a considerable height; and if there 

 should happen to be a natural fissure at c, a spring would be pro- 

 duced. Among the curious facts made known by the borer, is 

 the existence of distinct sheets of water, in Btrata of differen 



