176 SOILS: PROPERTIES AND MANAGEMENT 



Puchner * used a penetration apparatus, consisting 

 of a vertical shaft held by metal guides and counterpoised 

 by a weight hung over a pulley. The shaft was armed 

 at the lower end with a cutting blade, while the upper 

 end carried a scale pan for holding the necessary weights 

 for penetration. The cohesion coefficient was the weight 

 necessary to force the blade a certain distance into the 

 soil. All important apparatus have been modeled after 

 either Puchner's or Schiibler's. That of Atterberg 2 (see 

 Fig. 24) follows the former, while that of the Bureau of 

 Soils 3 (see Fig. 25) resembles the latter. 



Fig. 24. — Atterberg's apparatus for determining the cohesion of soil 

 prisms. The soil prism is placed between the cutting edge (K) and 

 the sharp plunger (P). Weights are added at (W). (C) is a coun- 

 terpoise. 



. ! Puchner, H. Untersuchungen iiber die Kohareszenz der 

 Bodenarten. Forsch. a- d. Gebiete d. Agri.-Physik., Band 12, 

 Seite 195-241. 1889. 



2 Atterberg, A. Die Konsistenz und die Bindigkeit der Boden. 

 Internat. Mitt. f. Bodenkunde, Band II, Heft 2-3, Seite 149- 

 189. 1912. 



3 Cameron, F. K., and Gallagher, F. E. Moisture Content 

 and Physical Condition of Soils. U. S. D. A., Bureau of Soils, 

 Bui. 50. 1908. 



