94 



SOILS. 



division, based upon the doubling of grain-sizes instead of 

 current-velocities, has been adopted by Prof. Milton Whitney, 

 of the U. S. Department of Agriculture, and others. 



TABLE OF DIAMETERS AND HYDRAULIC VALUES OF SEDIMENTS. 



Results of sucJi analyses. A tabular presentation of the re- 

 sults of analyses made in accordance with the above plan will 

 give a good idea of the differences between the various grades 

 of soils recognized in farm practice, to any one accustomed to 

 the study of figures. But a much more satisfactory showing 

 is made by placing the several grain-sizes segregated, into 

 small vials or tubes of identical diameter and placing them in 

 parallel series alongside of each other. 1 The curves formed 

 by the surfaces of the several sediment-columns in each series 

 show to the eye very strikingly the relations of the several 

 grades of soils to each other, and suggest at once that while 

 gentle slopes or gently undulating curves belong to soils of 

 intermediate, loamy character, steep grades and zigzags show 

 soils of extreme types. This is exemplified in the subjoined 

 Figures : 



1 Convenient stands for this purpose, used by the writer since 1872, may be cut 

 from L-shaped moldings of wood, such as can be readily ordered from any 

 planing mill. The vials can be cemented, wired or tied. 



