Joseph J. Skinner

“ 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 sensibly affecting the flow of those first sunk in the immediate neighborhood, while in other localities every new well either diminishes the flow of old wells or makes the level of the water in them sink. ”

“ In every particularly dry summer springs by the thousand are entirely dried up, and the flow from the majority of others is greatly diminished. On the other hand, in wet seasons all but the most extraordinary springs have their flow increased. In some geological formations increase of flow occurs very soon after the beginning of rains. Arago states as the uniform observation of miners, especially those of Cornwall, that in mines situated in the midst of certain limestones water increases in the deepest drifts a very few hours after it has begun to rain on the surface of the earth. ”

“ He adds, "Since flowing wells and springs are seldom if ever thus limited, we infer that the case supposed does not occur." On the contrary, we have every reason to believe that flowing wells and springs are almost always thus limited. Mr. Dickenson's observations, already quoted by Mr. Green, proved that the quantity of summer water in the river Colne varied with the rain in the preceding winter. ”

“ Green will have to charge this great decrease of flow to something besides increase of friction; for it is easy to see that, if the tube were extended up just to the point to which the water would rise without flowing out, there would then be no friction. In fact, the laws of hydraulics and hydrostatics have something to do with the subject of artesian wells. ”

“ That artesian wells are not sensibly affected by particular rainstorms is no proof that they are not ultimately supplied by rains, but only shows that the quantity of water furnished by the wells is exceedingly small compared with the total quantity at any time in the layer of porous material tapped by the wells. ”

“ Green makes his first imaginary difficulty by placing these wells "among the hills." He then quotes largely from Professor Buckland's address, and afterward exclaims: "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 which do not sink deeper than three feet!" ”

“ Clutterbuck 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 abstracted from the summer and autumn supplies of the river Colne. ”

“ His position plainly is (see p. 81) , that if any openings exist between bodies of water imprisoned in the earth's crust and the surface of the earth, these waters, unless entirely isolated bodies, would as a rule flow upward. If there were millions of cubic miles of water in accessible subterranean reservoirs, and no drain on them but that caused by the wells made by man, the supply might be considered "ample for all practical purposes," no matter how it got there or what forced the water up; but Mr. Green argues that not only flowing springs but the bulk of the waters of the rivers St. ”