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TRANSACTIONS OF THE 



to expect the presence of water in mines. The quantity 

 of this varies very much in different mines at the same 

 time, and in the same mines at different times. Some of 

 the circumstances which occasion this difference are very 

 obvious; for instance, the topographical relations of the 

 surface, the nature of the rock and lode, the number and 

 size of the lodes, cross course, &c. Many galleries, 

 both on the lode and through the country, are quite dry ; 

 but in general, the reverse is true. Commonly, the 

 water oozes almost imperceptibly from the lode and walls 

 of the galleries, and gradually accumulates, as formerly 

 mentioned, so as to form puddles and pools of considera- 

 ble size under the feet of the miners, and it is very com- 

 mon to find the bottom of long galleries covered, for some 

 hundred feet, with dirty water of this kind to the depth 

 of several inches, and sometimes of a foot or more , some- 

 times, but rarely, brisk streamlets or springs are met 

 with gushing from the lode. In most mines we meet 

 with currents of water flowing towards the pumps from 

 the upper galleries, or from parts of the mine that have 

 been abandoned. 



To prevent the works from being inundated, each 

 mine is furnished with a chain of pumps, extending from 

 the bottom to the surface, or adit level, if there is one, 

 worked by a single pump rod; each pump receiving the 

 water brought up by the one immediately below it. All 

 the water of the deepest level of the mine finds its way 

 into the bottom of the mine or sump, whence it is finally 

 elevated to the adit, through which it flows, by a gentle 

 descent, to the surface of the valley where the tail of 

 the adit empties itself.* 



The quantity of water discharged by the pumps from 

 many of the Cornish mines is very considerable, Huel 



* The water from the upper levels is received into cisterns placed in dif- 

 ferent parts of the shaft, at the termination of each tier of pumps, from whence 

 it is drawn to the adit. 



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