AGRICULTURE FOR SOUTHERN SCHOOLS. 
13 
To determine the relative weights of the soils use a can containing 
about a quart, the volume of which may be determined by the stu- 
dents. (Square cans are made especially for the purpose.) Weigh 
the empty can and then weigh it filled with each sample of soil in 
turn after it has been settled by jarring and made level by scraping 
off the top with the sharp edge of a ruler. Deduct the weight of the 
can to ascertain the weight of the soil. Compute the volume of the 
can and figure the weight of a cubic foot of each sample. 
Record and report: In making a record of these tests the following 
form may be used to tabulate results : 
Comparison of soil types. 
Kind of soil. 
Color. 
Amount 
of 
moisture. 
Amount 
of organic 
matter. 
Relative 
fineness 
of grains. 
Relative 
plastic- 
ity. 
Effect of 
water. 
Weight 
of cubic 
foot. 
Lesson 13. — Purposes of Cultivation. 
1. Preparation of seed bed. 
2. Control of weeds. 
3. Tillage in relation to fertility. 
4. Tillage in relation to moisture. 
Lesson 14. — Conservation of Moisture. 
1. Amounts of water used by plants. 
2. Losses by evaporation. 
3. The soil mulch. 
Exercise 10. — Rise of Capillary Water in Soils. 
Purpose: To determine the height and comparative rapidity of 
the rise of capillary water in soils of different types. 
Directions : Fasten securely in a rack four glass tubes 3 feet long 
and 1 inch in diameter. After tying cheesecloth over the lower ends, 
fill the tubes with the following kinds of soil, respectively: Clay, 
sand, loam, and leaf loam. The lower ends of the tubes should be im- 
mersed to a depth of 1 inch in a pan or glasses kept filled with water. 
Note the time the test is started and the height to which the water 
has risen in each tube at the end of the following periods: Ten 
minutes, 30 minutes, one hour, one day, three days, and six days. 
Record and report: Each student should tabulate the results of his 
observation, and in a written report to accompany the table answer 
the following questions: In which soil does the water rise the 
highest? In which does it rise most rapidly? Which soil has the 
greatest capacity for capillary water? Upon what factors does the 
