Faulty as Smeaton's design was in certain respects, it served as a model for lighthouse con struction in masonry which has been followed in its general features ever since.
The Bell Bock lighthouse, off the east coast of Scotland, is built upon a reef of rocks in the German Ocean. II miles from the coast, nearly opposite the Firth of Tay. The rock upon which it stands is red sandstone from 12 feet to 15 feet below spring tide, with from 2 feet to 4 feet ex posure at low tide. The tower is also of sand stone, but the facing masonry for a height of 30 feet is granite. It was designed by the cele brated engineers Robert Stevenson and John Ren nie, and was modeled after the Eddystone light house of Smeaton. its diameter at the base is 42 feet and at the top beneath the cornice it is 15 feet. The stonework is feet high and the top of the lantern is 115 feet high. Work was begun in 1807 and finished in 1810. The Sker ryvore lighthouse. off the west coast of Scotland. is built upon a cluster of rocks, the largest of which, known as Skerryvore rock, carries the lighthouse. The engineer was Allan Stevenson, who adopted a design fur the tower resembling more nearly the frustum of a cone than did the Eddystone and Bell Rock towers. The tower is circular, 42 feet in diameter at the base, DI feet in diameter at the top. and 138 feet high to the base of the lantern. Work was begun in 1838 and finished in 1842. Wolf Rock lighthouse, situ ated on Wolf Rock between Scilly and Lizard Point, off the English coast, has a tower in the form of a concave elliptical frustum 1161 feet high. 41% feet in diameter at the top. It was begun in 1862 and finished in 1869.
The Hi_laux de Brehat lighthouse is situated on the rock of the same name about three miles from the most northerly point of the peninsula of Brit tany. It consists of a tower with an interior cylindrical opening 14 feet in diameter. 158 feet high from its base to the lantern floor. The tower consists of two parts, the lower part be ing a concave frustum and the upper part be ing nearly a true cylinder. The lighthouse of Armen, which is situated on one of a series of rocks off Cape Finisterre, France, is another ma sonry lighthouse of French design which is no table for its exposed situation and the consequent difficulties of construction. The height of the focal plane of the light is 96 feet above sea-level.
The lighthouse of Triagoz, in the Department of Nord. is•another French example of exposed sea rock lighthouse construction. The masonry tower is square and 92 feet high, with the focal plane of the light 6 feet above this height.
In America, masonry lighthouse towers of notable character have been built at Minot's Ledge. Spectacle Reef, and Tillamook Rock. Minot's Ledge. off the town of Cohasset. in Massa chusetts Bay, about 20 miles east-southeast of Boston, is one of the most dangerous places in the world without a signal. The difficulties in the construction of a lighthouse upon this rock were immense. The first. structure, which was of iron. was completed in 1849. but stood only until April. 1851, when it was demolished by a terrific _ storm, in 1S52 money was appropriated by Con gress for a new lighthouse, and work was com menced in 1855, but it was not till the latter part of 1857 that the first stone was laid. The struc ture was completed in 1860. It is a granite tower in the form of a frustum of a cone, having a base 30 feet in diameter, and a height of stone work of 88 feet, the lower 40 feet being solid. The courses are dovetailed, and are fastened with wrought-iron dowels.
The lighthouse at Spectacle Reef, in the north ern part of Lake Huron, was built not only to resist waves, but ice-fields, often covering thou sands of acres and moving at the rate of two or three miles per hour. That the structure should be able to withstand this force, it was so designed as to cause the ice to he broken and piled into a protecting harrier. The tower is the frustum of a cone. 32 feet in diameter at the base, and 18 feet just beneath the cornice at a height of SO feet. The whole height of the stone work is 93 feet above the base, which is II feet below the surface of the water. The tower is solid as high as 34 feet, above which it contains five stories, each 14 feet in diameter. The work was commenced May I. 1870, and the light was first used June 1, 1874. The cost was 8375.000. Tillamook Rock is a bold isolated basaltic rock in the Pacific Ocean about a mile off Tillamook Head and 20 miles south of the Columbia River. The lighthouse on it, built in 1880-81, consists of a square masonry tower of no great height rising out of the centre of a masonry house 45 X 4S feet in plan, the tower proper being 11i feet square.