tion, and mix them together into a composite sample. No fixed 

 depth can be prescribed for the borings, but the actual depths 

 employed should always be stated in the notes accompanying the 

 sample. The surface soil should be sampled to the depth employed 

 in plowing or to the line of demarcation between soil and subsoil. 

 Twelve inches actual depth in the subsoil is a convenient standard 

 when the subsoil is sampled. 



About one quart of the composite sample will be sufficient for the 

 examinations in the laboratory, and the sample should be sent to the 

 Agricultural Experiment Station in a receptacle which the Experiment 

 Station will provide on request. 



The necessary information by which soils may be compared and 

 correlated is outlined in the following schedule, which is essentially 

 like that given in "Soils, Their Properties and Management," by 

 Lyon, Fippin & Buckman. 



Outline of Factors Useful in Soil Classification. 



Weathering 



( Stream 

 Water < Lake 



( Ocean 

 Wind 

 Glaciation 

 Gravity 

 Plant and Animal Life 



Agencies of Formation 



Materials of Formation 



Crystalline Rocks -! ^^'^'^^ 

 ( Basic 



Shales and Sandstones 



Limestone and Marl 



Organic Matter 



Specific Properties 



Color 



Natural Drainage 



Subsoil and Underlying Material 



Organic Matter and Humus 



Plant Food 



Carbonate of Lime 



Texture 



Sizes of Soil Particles 



