SOIL STRUCTURE 175 



Schiibler's, 1 in which was tested the resistance of rec- 

 tangular prisms of dry soils to penetration by a steel 

 blade. The apparatus consisted of a beam supported 

 on a fulcrum more than one third of the distance 

 from the end. A pan for holding the weights added 

 for causing the crushing was hung at the end of the 

 long arm, while a counterpoise on the short end of the 

 beam acted as a balance. The steel knife was placed 

 on the long end of the arm near the fulcrum. The dry 

 soil prism was placed under the knife and weights were 

 added to the pan until crushing occurred. The weight 

 necessary was designated as the cohesion coefficient of 

 that soil. 



Haberlandt 2 measured cohesion by crushing soil 

 cylinders of a definite size. A glass vessel was placed 

 on the top of the column and water was added until the 

 column gave way. The weight necessary to bring this 

 about was designated as the absolute cohesion of the 

 sample. Haberlandt also measured cohesion of soil 

 cylinders of a definite size by determining the resistance 

 to breaking under a transverse load, the soil column being 

 placed across supports six centimeters apart. On the 

 column midway between the ends a scale pan was sup- 

 ported, into which weights were put until breaking oc- 

 curred. The figure thus obtained was called the relative 

 cohesion. 



1 A good description of Schiibler's apparatus is found on page 

 104 of Bodenkimdo, by E. A. Mitscherlich, published by Paul 

 Parey, Berlin, in 1905. 



2 Haberlandt, H. Ueber die Koharescenz Verhaltnisse 

 verschiedener Bodenarten. Forsch. a. d. Gebiete d. Agri.- 

 Physik., Band I, Seite 148-157. 1878. Also, Wissenschaftlich 

 praktische Untersuchungen auf dem Gebiete des Pflanzenbaues, 

 Band I, Seite 22. 1875. 



