728 SOILS: FBOFEBTim AND MANAGEMENT 



of about thirty-eight inches. By the use of additional 

 sections the length may be increased. The end of the 



auger may be modified by cutting off 

 the screw and the cutting jaws, to 

 better adapt it to the work in soil. 

 Generally a bottle of muriatic acid 

 for detecting carbonates, and strips 

 of sensitive litmus paper of red and 

 blue for testing for soil acidity, are 

 useful adjuncts to the equipment. In 

 arid regions where important quanti- 

 ties of alkali are met with, the field 

 man should be supplied with a modi- 

 fied Wheatstone bridge and chemical 

 equipment necessary for the detection 

 and measurement of the important 

 salt constituents.^ A geologist's ham- 

 mer for examining soil and rock should 

 be added, together with such other 

 minor equipment as may increase the 

 convenience and efficiency of the work. 

 A substantial field book should be 

 provided, for notes on the character 

 of soil types and other observations 

 and data, and for records of borings 

 and samples. The notes should be 

 carefully classified. Muslin bags of 

 about one quart capacity should be used for collecting 

 and shipping the samples to the laboratory for mechani- 

 cal analysis. Where the natural field structure and 



^ Davis, R. 0. E., and Bryan, H. The Electrical Bridge 

 for the Determination of Soluljle Salts in Soils. U. S. D. A., 

 Bur. Soils, Bui. 61. 1910. 



Fig. S3 —Auger used 

 m the examination 

 of soils. {A), 

 handle ; {B) , joint ; 

 (C) , worm with 

 ipodified cutting 

 edge. 



