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THE JOURNAL OF GEOLOGY.
Observations and Experiments on the Fluctuations in the Level and Rate of Movement of Ground-water on the Wisconsin Agricultural Experiment Station Farm, and at Whitewater, Wisconsin.By Franklin H. King, Professor of Agricultural Physics, University of Wisconsin.(Washington D. C.: U. S. Department of Agriculture, Weather Bureau, Bulletin No. 5. 75 pp. Ill., 6 plates).

This bulletin records observations made on the fluctuations of the underground water level from 1888 to July 1892. For the purpose of these observations forty-six wells, varying on depth from five feet to eighty-four feet, within an area 1,200✕1,000 feet were available. There are certain short-period changes in level of the ground-water. (1) Those due to seasonal and annual changes in rainfall. (2) Seasonal and mean annual changes in soil temperature develop fluctuations by modifying the rate of percolation and of underground drainage, the changes in temperature influence the viscosity of liquids, and variations in viscosity affect the flow of water through capillary tubes of the soil. Besides these changes the surface of the ground-water level is subject to many slight oscillations, some of them almost beyond measurement. "Oscillations of atmospheric pressure of almost every character affect the under groundwater surface. The longer period barometric changes associated with cyclones, the shorter period changes which accompany thunder storms, and semi-diurnal barometric changes have their corresponding fluctuations in the ground-water." It was found that in recording the rate of flow of a tile drain, a spring and an artesian well, that all three had fluctuations synchronous with the barometric fluctuations. The magnitude of these influences is so great that Prof. King thinks the change in flow from large subterranean drainage areas can be registered upon many rivers and lakes. "The equilibrium of the water, in the capillary soil spaces above the surface of the ground-water, is so unstable that apparently the slightest cause is sufficient to upset it, causing the water to flow out of the non-capillary spaces, but only to be returned again on a moment's notice." The diurnal changes in soil temperature produce corresponding rises and falls of the water surface; "the passage of a train, even where the water is twenty feet below the surface, causes the non-capillary spaces to fill up and empty again as the weight approaches and recedes." No fluctuations due to lunar or solar tidal disturbances were observed.

C. E. P.

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