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in arid climates. But into whatever land man has gone, humid as well as arid, springs have had a part in his activities. So far as America is concerned, I am not aware that a quantitative study of the influence of springs in humid regions has been undertaken.

While mapping the stratigraphy of an area of approximately 25 square miles in central Ohio, where the annual precipitation is about 40 inches, the influence exercised by springs was given particular attention. In this area the upper formations of the Mississippian, and the lower of the Pennsylvanian periods come to the surface. The vertical series of rocks involves two horizons of coarse clastic sediments, the Black Hand of the earlier period, and the Sharon member of the Pottsville, which is the lowest formation of the later period. The Black Hand overlies the Cuyahoga, which in central Ohio "is composed largely of bluish and grayish shales and buff sandstones." Subjacent to the Sharon is the Logan formation consisting chiefly of "buff arenaceous shales to thin bedded sandstones." The Black Hand is a massive sandstone, locally conglomeratic; the Sharon is less massive, and locally coarser; this characterization of these two formations applies specifically to the area studied. While neither of these sandstone formations overlies impervious beds, yet in themselves they are variable in texture and structure, and the region is so maturely dissected, that conditions are very favorable to the development of springs. Furthermore, the Logan also contains beds that are water-bearing.

The early settler in agricultural lands found a spring, if possible,