Page:Popular Science Monthly Volume 71.djvu/57

Rh In all, six attempts had been made to capture the runaway river before the last and successful one. The first five, however, were poorly carried out and practically amounted to nil in the final success. The sixth proved better, and for a time it seemed to solve the problem. It was completed on November 4, 1906, and on the night of December 7, 1906, during the flood, the river again ate its way through the barrier of willow matting, piles, rocks and dirt and once more wended its way toward Salton Sink. This dam, called the Hind Dam, in honor of the field engineer, Thomas J. Hind, therefore withstood the rebellious-inclined Colorado for a period of only thirty-three days.

The Hind Dam, which, though not a success of itself, aided in the final capture, was a conglomerate creation 170 feet wide at the base, 30 feet across at the top and 35 feet high at the deepest places in the break. It was 3,000 feet in length, of which 600 feet was of rock construction and 2,400 feet of earth and gravel. Its foundation consisted of a heavy, strong mat of willow and cable, held in place by strong piles, about 1,100 in number and from forty to sixty feet in length. The mat was created by the use of 2,200 cords of willow, cut by Indians, 40 miles of five-eighths-inch woven steel cable, and 10,000 cable clips. It was 100 feet wide and 800 feet in length, divided into eighteen sections, and was laid across the river by being uncoiled from a barge floated across the stream.

The piles driven into the mat were also made to serve as a support for a temporary railroad. From this road carload after carload of material was dumped into the gap, in all there being 70,000 tons of rock, 40,000 cubic feet of gravel, 40,000 cubic feet of clay, and 100,000 sacks of sand, besides about 500,000 yards of dirt thrown up by teams and dredges. To carry on this work as many as 1,100 men and 600 horses and mules, besides several steam dredges, shovels, pile drivers and an almost endless string of freight cars, were employed at one time. The cost of the work to the Southern Pacific Railway Company, which, headed by Engineer Epes Randolph, engineered the undertaking, reached an average rate of $10,000 per day for one hundred days.

The break that occurred in the river after this dam was completed, in December, was at a part about 2,500 feet below the works, and was 1,100 feet wide. Colonel Randolph again assembled his forces, placed E. K. Clark, engineer of the Tucson division of the Southern Pacific Railroad, in direct charge, and work was recommenced to solve this troublesome problem. Another dam, called the Clarke Dam, was built and by it the Colorado River has at last been permanently confined to its old channel.

To build this dam no attempt to follow science was made. The Southern Pacific placed their entire road subject to the orders of the