SUGGESTIONS TO TEACHERS 



This little book of soil experiments has been prepared 

 in response to the demand for a brief laboratory and field 

 course in elementary soils, which may be given without 

 the purchase of expensive equipment. With a few tools 

 and the aid of the pupils, the teacher should be able to 

 construct all of the apparatus necessary for many of the ex- 

 ercises. Such cooperation on the part of the students will 

 stimulate a keener interest in the work than can be secured 

 by the exclusive use of purchased materials. However, as 

 funds become available, it is advised that special equip- 

 ment be purchased and substituted for the less satisfac- 

 tory, home-made apparatus. 



In many schools apparatus from the chemical and 

 botanical laboratories will be available for the soil w^ork. 

 For example, a good balance may be purchased for the 

 joint use of the chemical and soils laboratories, and the 

 compound microscope may serve for both botany and 

 soils. The first purchase of equipment should include 

 the following: 



1. Gasoline or kerosene stove with oven. 



2. Balance similar to the one shown in Exercise A-7. 



3. Soil auger and spade. 



4. Small equipment, such as sample cans, glass tumblers, 



tin cans, wrapping paper, cheese cloth and twine. 



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