TUNNEL (ate). One of the most important tunnels in the United States is the Hoo sac tunnel in Berkshire co., western Mass., owned by the state, is an important Dart of the Fitchburg railway from Boston to the west. The e. end of the tunnel is 137 in.
from Boston. Some preliminary work was undertaken in 1651, but the actuat cutting of the mountain did not begin till 1856. In 1862 the work came into the hands of the state, which brought it to completion. The tunnel is 42- tn. loug, running through mica ceous schist, and of sufficient width to permit the laying of two railway tracks. The work of cutting was chiefly done by pneumatic drills. The entire cost of the tunnel is not easily stated, but with some 40 m. of railroad, it probably approached $15,000,000. It is now in constant and successful use, and few lives have been lost in the work of its con struction.—A subaqueous tunnel to supply the city of Chicago whit pure water front lake Michigan extends 2 m. into the lake easterly, having two Awns, 6 and 7 ft. in (liana ;cr. Work was begun on the first shaft in 1864 and completed in 1867; the second was flu): lad in 1874. On the crib, 2 in. in the lake, is a light-house and keeper's house. The catire cost of the city water-works up to 1874 was somewhat more than 5,000.000. The chief difficulty encountered in the construction of this tunnel was front explosive gas, and several accidents occurred from this cause, none of which, however, were fatal. The
quality of the water thus furnished to the city has been as a rule very good, though in the summer of 1881 unusual causes drove the city sewage for a short time to the mouth of the crib. Somewhat similar' tunnels have been built at Buffalo, N. Y., and Cleve land, Ohio. The latter is 6,C60 ft. long and 5 ft. in diameter. In its constructicn dilly culties were encountered, as at Chicago, from volumes of inflammable gas, which from time to time entered it and exploded. Sofa lives were thereby lost. The work was begun in 1869 and finished in 1874. at a cost of somewhat less than $::50,CC0.—A railway tunnel under the Hudson river at New.Yerk is designed to give that city railway con nection with the west. Work is at present (1881) slowly going on at the western end. It was for a time interrupted by a fatal accident. a considerable body of ground caving in.—Of the various miniug tunnels in the United States the most notable is that at Sutro, Lyon co., Nev., about 10 m. s. of Virginia City. The tunnel. which opens the Comstock lode of silver, is about 4 in. long and has cost about 8.:5,000,000. See CENIS, 31ONT, aide, and GOIIIARD, ST. ante.