Cost of Underdrawing 489 



and the level of the ground water be thus lowered. 

 The reason for this is that the quicksand character 

 is due to the water being forced up through the fine 

 sand, which has little adhesion between its grains, 

 and the water tends to float the sand, thus causing it 

 to run with unusual freedom ; but when the water is 

 given time to drain away, so that the sand is no 

 longer full of it above the bottom of the ditch, it 

 becomes firm, and the tile may then be laid. 



COST OF UNDERDRAINING 



It is not possible to give the cost of draining land 

 without knowing all of the details which go to make 

 up the total expense ; but certain general statements 

 may be made, which will enable any one to compute 

 for himself what the cost is likely to be. 



In the case represented by Figs. 159 to 163, the 

 work was done by a professional drainage engineer at 

 an average cost of $3 per 100 feet for digging and 

 laying the tile, and 30 cents per 100 feet for filling 

 the ditches, thus making the labor after the tile had 

 been placed upon the ground $3.30 per 100 feet, 

 including the board of the men. The ground drained 

 in this case was such as to represent about average- 

 conditions, where the spade may be readily put into the 

 soil with the pressure of the foot, where no stones or 

 quicksands are encountered, and where the main has 

 a depth of 3 to 5 feet, and the laterals an average 

 depth of 3 feet. In the case represented in Fig, 141, 

 Mr. Elliot gives the cost of the different items as 

 expressed in the table which follows: 



