Page:Popular Science Monthly Volume 16.djvu/91

From Wikisource
Jump to navigation Jump to search
This page has been validated.
WHY DO SPRINGS AND WELLS OVERFLOW?
81

every point of the inside surface of the supposed rock-prison. The intensity of this resultant will be represented by the aggregation of all the resultants of all the particles of water. Now, suppose a small opening to be made in this rock-prison. Immediately, the water will be forced out with a velocity equal to the influence of these aggregated resultants modified by the laws of friction, and this velocity will not be at all influenced by the direction of the original impulses given to the water-particles. Although the direction of the resultant itself is say 45° from the direction of the force of gravity, its transmitted force will be unimpaired should the opening lead in a direction opposed to gravity, or in fact in any direction, since the tendency of water expansion or reaction under pressure is uniform in all directions. Moreover, since the resultant has been shown to be greater under all circumstances than gravity, certainly the vast aggregations must also be greater than the aggregated gravity, and will be able to overcome it under the conditions stated.

Hence, if fissures exist in rocks that lead to imprisoned waters it would happen that through these outlets the waters must certainly flow; and, if by any artificial means, as by boring, an opening should be made between a body of confined water and the surface of the earth, a flowing well would result.

But, of course, it must be understood that this would not happen if the body of water supposed were an isolated one and completely unconnected with other bodies of water through channels and intercommunications known to exist in the various ramifications of the earth's surface. The subterranean water circulation which interpenetrates the crust of the earth is clearly caused by the centripetal and centrifugal forces of nature, reënforced no doubt often by differences in temperature and other minor causes. And it also might and probably does occur that the overflowing of a well or spring is due to the fact that the water flows from a higher to a lower level, but this will be found to be too rare to form a rule.

The intensity of the centrifugal force will increase with the distance from the center of the earth, while gravity will decrease; the resultant will also increase. Thus, we find the strongest and most abundant overflows at the tops of mountains or on high plateaus. But suppose it had been fully proved that a particular overflowing spring was caused by hydrostatic pressure, it would still remain to be accounted for how the water got to that higher point. This can best be done by the force demonstrated, which is always acting upon the partially confined water-beds and water-channels forming the internal water-structure of the earth's crust. The conditions necessary to the realization of the best results are that these water-deposits shall be more or less imprisoned and the outlets comparatively limited. The overflow will be continued and upward until the resultant is overcome by friction. The lengthening of the channel of overflow, as in the