34 
BULLETIN 300, U. S. DEPARTMEXT OF AGRICULTURE. 
and cost $115,000. Once dining this season the dredge was sunk to 
the bottom of the canal; otherwise, the work was done under favor- 
able conditions and the excavation made was representative of the 
capacity of the machine in ordinary clay soil. 
Cost of excavation by hydraulic suction dredge on the New York Barge Canal for the 
season 1908. 
Month. 
Total 
Labor. 
Plant* 
Material. 
for 
month. 
Dollars. 
Dollars. 
Dollars. 
Dollars. 
3,670.95 
408. 30 
1,900.62 
5,979.87 
5, 169. 29 
1,367.60 
2, 558. 88 
9,095.77 
5,615. 75 
1,677.85 
2,263.16 
9, 556. 76" 
5, 835. 14 
1,735.50 
2, 446. 45 
10,017.09 
5,985.87 
1, 631. 15 
2,320.92 
9, 937. 94 
4,993.11 
1,692.85 
2. 430. 05 
9,116.01 
4,834.14 
1,791.15 
2, 573. 50 
9, 198. 79 
Yards 
exca- 
vated. 
April 
May 
June 
July 
August 
September . 
October. . . 
120,673 
204,838 
203,474 
207,520 
174,395 
231,473 
214,438 
1 Interest and depreciation at 15 per cent per annum. 
Average cost for the season, 80.0464 per yard. 
USE IN CONSTRUCTION OF LEVEES. 
It formerly was considered that the hydraulic dredge was not 
applicable to levee construction for the reason that the large amount 
of water pumped made it difficult to keep the solid material from 
spreading over a wider base than desired for the levee. It was gen- 
erally thought necessary to build ridges to form the toes of the em- 
bankment, with earth dry enough to hold the wet material within 
the desired limits until the solid matter had been deposited; in this 
manner one layer was added to another until the desired height of 
levee was reached. The need of this dry material is avoided by 
methods now in use by which the entire section of the levee is built 
in one operation. 
Plate VIII and Plate IX, figure 1, illustrate the method of forming 
the desired slopes by means of steel boards about 18 inches wide and 
10 feet long, made of No. 14-gauge steel with angle-iron top. These 
boards are not too large nor too heavy to be easily moved by one man. 
In Plate VIII, figure 2, the slope boards are easily seen; they are 
placed at the intersection of the side slope with the natural slope of 
the end of the fill under construction. Several men equipped with 
shovels are necessary to distribute the material evenly and to move 
the slope boards ahead as the levee is built up. 
On a section of levee built along the Mississippi River near Bur- 
lington, Iowa, a hydraulic dredge consisting of a hull 24 by 80 by 
4J feet, upon which was mounted a centrifugal pump having a 12-inch 
suction pipe, a 14-inch discharge pipe, a 200-horsepower engine, and 
a boiler nominally rated at 150 horsepower, was used for the con- 
struction. The discharge pipe was carried from the dredge to the 
