640 EXPEEIMENT STATION RECORD. 



soil was easily and uniformly brought down to the mark, and all the old trouble 

 with the uneven distribution f)f the soil particles, when poured into the cylinders, 

 was avoided. 



"The standard of compactness for each class of soils was obtained l)y weighinj^ the 

 quantity which could be conveniently settled or compacted into 100 cc. of space by 

 tapping the sides and bottom of the cylinder — not by tamping the soil itself. The 

 weight of the soil thus obtained was adopted as the weight per unit of volume 

 throughout the experiments with that soil." 



The results of determinations by this means of the rate of flow through a number 

 of different kinds of soil (black adobe, loam, and sandy soil), the materials dissolved 

 by the percolating waters, and the effect of alkali on percolation are reported in detail 

 in tables and illustrated in diagrams. "The sandy soil, which it was confidently 

 expected would show the fastest rate of flow, was very much the slowest of the 

 three almost from the start, being 62 hours behind the loam and 45 hours behind 

 the black adol)e at the 40-in. mark." This is attributed to the fact that the sandy 

 soil had been proportionate!)' more compacted than the others and had a lower per- 

 centage of interspace. It was found that a very small difference in the percentage 

 of interspace caused enormous differences in rate of percolation, emphasizing "the 

 extreme liability of laboratory experiments of this kind to variable results, unless 

 a full knowledge and control of ail conditions are obtained before comparisons and 

 deductions are made." The amounts of soluble matter removed by the percolating 

 water were large, especially in the first percolates, but data so obtained are not con- 

 sidered a safe basis for estimates of what occurs in nature. The results of the 

 studies of the influence of alkali on percolation were not considered conclusive. 



The motions of underground waters, C. S. Slichter ( Wafer Suj^^^ly and Irrig. 

 Papers, U. S. Geol. Survey, No.67,]>j). 106,ph.S, fajn.SO). — A preliminary discussion by 

 the same author of experimental and theoretical considerations relating to the move- 

 ments of underground water has already been noted (E. S. E,., 11, p. 519). "The 

 present paper treats of the simpler and more general topics connected with the 

 movements of water underground, being intended to answer the more elementary 

 questions which arise in a consideration of the subject. Examples are given of the 

 various areas in which water occurs underground, the origin and extent of the 

 waters are discussed, and methods of bringing them to the surface and making them 

 available are touched upon. To determine the rate of movement of the underflow 

 the author made a series of observations along the dry bed of the Arkansas River, 

 western Kansas, by the following means: A double row of Ij-in. drive wells was 

 sunk across the channel of the river. The upstream wells were then charged with 

 a strong electrolyte, which dissolved and passed downstream with the moving 

 water. Ammonium chlorid was found most satisfactory for this purjiose. The pas- 

 sage of the electrolyte toward the lower well was shown l)y the gradual movement of 

 the needle of an ammeter, and the final arrival at the well was shown by a sudden 

 and strong deflection of the needle. 



Not only are the surface zone of flow and the flow through underground channels, 

 sand, gravel, etc., discussed in this paper, but also the deep zones of flow and the flow 

 through rocks of various kinds, as well as common open wells and artesian and deep 

 wells. 



Field operations of the Bureau of Soils, 1901 (third report), M. Whitney 

 ET AL. ( [7. S. Dept. Agr., Field Operations of the Bureau of Soih, 1901, pp. 647, pis. 

 96, figs. 25, maps 31). — This report gives a general review of the work of the Bureau 

 during 1901 by the chief of the Bureau, together with the following papers by assist- 

 ants in charge of field parties: Soil Survey of the Westfield Area, New York, by 

 R. T. A. Burke and H. W. Marean, Soil Survey of Allegan County, Mich., by E. O. 

 Fippin and T. D. Rice; Soil Survey of the Salem Area, New Jersey, by J. A. Bon- 

 steel and F. W. Taylor; Soil Survey ot the Lebanon Area, Pennsylvania, by W. G. 



