AMOUNT OF WATER MOVED 



187 



clay soil was in a very well-granulated condition, which 

 brings its rate very near that of the sand. It also appears 

 from this data, as was shown in the data on height 

 and time of capillary rise, that, up to three or four feet, 

 the fine sand is as efficient as the soil of much finer 

 texture. 



In studies on the capillary rise of water in moist Sea 

 Island cotton soil a fine sandy loam, Briggs found 



Fig. 59. The weeder, with riding attachment. For very shallow cultivation 

 in mellow soil free from stone and rubbish. 



the movement to be at the rate of 1.3 pounds per square 

 foot per clay, or 91 inches per year, through a height 

 of 85 centimeters (34 inches). But when the column 

 of the sand soil was 165 centimeters long, water was 

 raised at the rate of .32 of a pound per square foot per 

 day, or 21.4 inches per year, a decreased efficiency 

 from doubling the height of the column of 75.4 per cent, 

 When the column was 185 centimeters in height, no 

 appreciable loss took place, indicating that this sand 



