WHY DO SPEnYGS AND WELLS OVERFLOW? ji 



may be surprised at the knowledge geologists profess to have acquired 

 respecting the internal structure of the earth, he (the Professor) would 

 endeavor to confirm the above theoretical explanation of the origin 

 and supply of springs by appealing to practical proofs in the proceed- 

 ings of water companies and well-diggers, and in the pounds, shillings, 

 and pence in the ledgers of manufacturers." It certainly must be a 

 matter of " surprise " to most people that, while the rain-water rarely 

 sank deeper than three feet into the soil, it could yet influence the 

 water-supply to be drawn from deep wells in the earth, so much as to 

 draw upon the water-supply of the river Coin, which like that of all 

 rivers is more or less dependent upon surface influences in addition to 

 overflowing springs. Wells to supply London, the Professor thinks, 

 must not be utilized to draw water from a depth of thirty or forty feet 

 because it would cut off the supply due to the rains Mdiich do not sink 

 deeper than three feet ! It should have been the easiest possible thing 

 to supply London without in any way drawing upon the supply of the 

 river Coin, since the river and the wells draw from different sources. 

 The learned Professor had no idea of the existence of any force in the 

 premises other than hydrostatic pressure, and yet he proceeds in the 

 next paragraph to give important evidence of some other force : 



" In Germany, Mi-. Buckmann, of Heilbronn, published in 1835 an 

 octavo volume on artesian wells in the valley of the Necker, from 

 which it appeared that there were manufactures in Wurtemberg near 

 Constadt 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 Heilbronn, also, there were persons who saved the expense of fuel 

 by conducting artesian warm water in pipes through their houses and 

 greenhouses. . . . Let those who doubt go to Grenelle and see the 

 majestic column of warm water from the philosophically discovered 

 fountain rising thirty feet above the surface, at the exact temperature 

 foretold by Arago, and learn the correctness and value of practical 

 deductions from geology applied to the useful purposes of life." 



From which quotations it appears that the Professor is in a remark- 

 able position. At Wetford these wells could not be utilized because the 

 river-supply of the Coin would be exhausted ; but in Germany they 

 were a new and important source of supply to the rivers themselves. 

 Imagine the " majestic column " at Grenelle rising thirty feet high and 

 the overflow in the other cases being due to hydrostatic pressure — i. e., 

 due to the fact that all these immense floods were the result of a flow 

 from some other higher bodies of water. Why did it not occur to 

 Professor Bucklarid that, however high and abundant the source, such 

 drains must of necessity have sooner or later exhausted the supply, if 

 no equivalent streams were flowing into that also ? But suppose this 

 to be so, whence could come the higher head to flow into and supply 

 that in turn ? Carry this on until a flow is secured from the high- 



