The Shoshone Dam is a masonry dam built by the United States Reclamation Service in Wyoming near Cody. It is 324 feet high, curved upstream, 10 feet thick at the crest, and 108 feet thick at its base, which thickness is continued up to the level of the river bed. The Roosevelt Dam was also constructed by the United States Reclamation Service. It is located in Arizona, has a maximum height of 284 feet, a storage capacity of 420,000,000,000, and was completed in 1911. The Arrowrock, near Boise, Idaho, construction of which was started in 1914 by the same Government agency, is 354 feet high, and 1,060 feet long. It The highest earth dam ever attempted is the Calaveras Dam of the Spring Valley Water Company of San Fran cisco. This dam is 240 feet high, the crest length is 1,300 feet, the base is 1,300 feet wide, the upstream slope is 3 to 1, and the down stream slope is to 1. It is a hydraulic fill dam.
The new Croton Dam of the New York City Water Supply System was completed in 1907, and provides a stor age capacity of 32,000,000,000 gallons of water. It is a masonry dam with a crest length of 2,168 feet, and a height of almost 300 feet. There is a roadway on the top of the dam. The spillway is 1,000 feet long, and varies in width from 50 to 125 feet.
is curved upstream, with a gravity sec tion, and is built of concrete.
The Keokuk Dam, which crosses the Mississippi river at Keokuk, Ia., is a 'ong, low concrete dam. Besides the spillway section, 4,278 feet long, there is an abutment 290 feet long, a combina tion, another 1,700 feet long, in the form of a power house, and a lock section of about 600 feet.
The Elephant Butte Dam, located near Engle, N. M., was dedicated on Oct. 19, 1916. It is a Reclamation Serv ice dam of rubble concrete, with a gravity section. It is 1,200 feet long and 304.5 feet high from base to top.
The hydro-electric development dam of the Yadkin river, N. C., contains a dam built of concrete, 1,400 feet long, and 217 feet in height.
The Noguera Pallaresa River Dam in Spain was built and designed by Ameri can engineers. It is 330 feet high, 700 feet long, has a base width of 230 feet, and is built of concrete.
The deep water plans for the Missis sippi river include the construction of numerous darns, and in 1917 Darn No. 1, located near St. Paul, was placed in operation. It made the river available for navigation for 13 miles.
In New South Wales the Murray River Darn has been planned as part of an irrigation project. It will be 3,600 feet long, and have both earth and con crete sections.
In 1864 a poorly constructed earth dam at Sheffield, England, went out the first time it was put to use, and caused a flood which cost 238 lives. No en gineer was employed to design the Mill River Dam at Williamsburg, Mass., which went out in 1874, with a loss of 143 lives, and $1,000,000 in property. The The Hetch Hetchy Darn of the San Francisco water system will be one of the largest masonry dams in the world. The height from foundation base to crest will be 311 feet. It will be a masonry dam with a straight gravity section of 600 feet, and will have a siphon spillway. It will be located in the Tuolumne river 150 miles E. of San Francisco.
South Fork Darn, owned by the South Fork Hunting and Fishing Club of Pittsburgh, Pa., was an earth dam of 70 feet height. It was designed to have a spillway of 150 feet, but this was not carried out, and the existing spillway was partially blocked with screens, bridge supports, etc., when in May, 1889, excessive rains caused the water to go over the entire length of the dam. The dam itself was carried away, and flooded the town of Johnstown, Pa., with a loss of over 2,000 lives and about $4,000,000 in property. The Walnut Grove Dam in Arizona failed on Feb. 22, 1890. This dam was a rock-fill structure, and the failure was caused by inadequate spill way. The Colorado River Dam at Austin, Tex., failed in 1900 because of poor foundations; and because of faulty construction, the concrete dam at Austin, Pa., failed on Sept. 30, 1911, and cost 35 lives. Because of structural weak ness caused by improper drying of the materials, the Lyman Dam across the Little Colorado river in Arizona, failed in 1915. In 1916 an old dam near Gab lonz, Bohemia, failed, with a loss of over 300 lives.
DAMAN (0.-man'), or DAMAO, a fortified post and district in India, be longing to Portugal since 1558, on the Gulf of Cambay, 100 miles N. of Bombay. The climate is generally healthy, the soil moist and fertile. The chief products are cereals, rice, tobacco, and wheat, and there are also important deep-sea fisheries and salt works. Ad ministratively the district belongs to GoA (q. v.). Area, 170 square miles; Pop. about 75,000.