208 THE JOURNAL OF GEOLOGY. 



Observations and Experiments on the Fluctuations in the Level and Rate of 

 Movement of Ground-water on the Wisconsin Agricultural Experi- 

 ment Station Farm, and at Whitewater, Wisconsifi. By Franklin 

 H. King, Professor of Agricultural Physics, University of Wis- 

 consin. (Washington, D. C: U. S. Department of Agriculture, 

 Weather Bureau, Bulletin No. 5. 75 pp. 111., 6 plates). 

 This bulletin records observations made on the fluctuations of the under- 

 ground water level from 1888 to July 1892. For the purpose of these obser- 

 vations forty-six wells, varying in depth from five feet to eighty-four feet, within 

 an area 1,200X1,000 feet were available. There are certain short-period 

 changes in level of the ground-water, (i) Those due to seasonal and annual 

 changes in rainfall. (2) Seasonal and mean annual changes in soil temper- 

 ature develop fluctuations by modifying the rate of percolation and of under- 

 ground drainage, the changes in temperature influence the viscosity of liquids, 

 and variations in viscosity affect the fl.ow of water through capillary tubes of 

 the soil. Besides these changes the surface of the ground-water level is sub- 

 ject 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 barometic 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 synchron- 

 ous 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 equilib- 

 rium of the water, in the capillary soil spaces above the surface of the 

 ground-water, is so unstable that apparently the slightest cause is suffi- 

 cient 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 sur- 

 face, 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 dis- 

 turbances were observed. C. E. P. 



