22 THE OLIVER PLOW BOOK 



finely pulverized soil. Clay has the smallest soil particles ; 

 clay loam the next larger, loam larger than clay loam; 

 sandy loam larger than loam; and loamy sand larger than 

 sandy loam. This pan was filled with water, giving it 

 an opportunity to rise in the tubes by capillarity. 



The five samples of soil in these tubes were taken from the same farm. 

 They are shown on pages 39, 41, 43, 45 and 47. At the top of each tube 

 is a granular mulch. The particles of earth are much coarser than those 

 of the finely compacted earth below. These tubes are eight inches high 

 and two inches in diameter. The earth was packed in each tube to bring 

 about an ideal condition for capillary attraction to act. The soil was 

 also placed in an ideal condition for germination of the seed and the 

 growth of the plant. The surface was not. Do not fail to observe the 

 effect of this granular mulch in the illustration on page twenty-four. 



The illustration at the top of page twenty-three 

 shows the water is almost halfway to the top of 

 the finely pulverized earth in the tube of the loamy 

 sand; has a good start in the sandy loam; is just 

 beginning in the loam; is hardly perceptible in the clay 

 loam, and not at all in the clay. Thus, we observe that 

 up to this period capillary attraction is faster in the 

 sandy soils than the clay, and that the loam is about 

 midway between. 



The second illustration on page twenty-three shows 

 the water in the tube filled with clay has just started 



