In France, the lighthouses and harbour lights are all under a public board ; and the expenses are paid out of the treasury, and met by levying a port charge of 10d. per ton upon shipping generally. In 1815 there were 52 general coast lighthouses, and 101 harbour lights. In America, as in France, the light houses are maintained by the government.
We will here briefly describe the three most notable lighthouses of modern times ; viz., the Eddystone, the Bell-rock, and the Skerry yore.
Eddystone.—The Eddystone is the name of a rock which lies about 12 miles south-west of Plymouth Sound, in a position peculiarly dan gerous for ships entering the Sound. A light house was built on this rock in 1696, but blown down by a storm in 1703. A second was built in 1706, and burned down in 1755. The pre sent lighthouse was planned by Smeaton in 1756, and finished a few years afterwards. It is a circular tower of stone, sweeping up with a gentle curve from the base, and gradually diminishing to the top. The upper extremity is finished with a cornice, and surmounted by a gallery and lantern, The tower is furnished with a door and windows, and an interior stair case and ladders. The granite Eddystone rock was partly wrought to form a foundation; and the dressed stones (granite at bottom and limestone at top) were dovetailed to the rock in a manner calculated to give immense strength. These stones were generally from one to two tons weight each. The base of the lighthouse is about 27 feet in diameter, and the entire height is about 86 feet.
Bell Rock.—About twelve miles from Ar broath, on the Forfarshire coast, is a dange rous rock called the Bell or the Inchcape Rock. On this rock Mr. Stevenson built a beautiful lighthouse, which was finished in 1811. The foundation is 42 feet in diameter, and is built solid to a height of nearly 40 feet, every stone being dovetailed into those Which surround it. The higher or hollow part of the building is divided into six rooms, used as a fuel room, an oil room, a kitchen, a bedroom, a library, and the light-room. There are two large bells belonging to the building, to be rung when the weather is too foggy to permit the lights to be seen from a distance.
Skerryvore.—In the Atlantic Ocean, between the Hebrides and Ireland, are many dangerous half-hidden rocks, which have occasioned nu merous shipwrecks. On one of these rocks, called Skerryvore, a lighthouse has been built in recent years, under circumstances of im mense difficulty. Mr. Alan Stevenson under took the work in 1834, but it was not till 1844 that the lights were exhibited. The rock is l2 miles from a small island called Tirree ; and Tirree is two or three days' sail from any part of the coast whence supplies could be ob tained; hence the difficulties encountered by the engineers and workmen were most haras sing. It was at all times difficult to approach
the rock ; and when there, the number of working days in a year was very small ; the rock itself is excessively hard, and the difficulty great of transporting stones thither. But all difficulties gradually gave way to the skill and perseverance of the engineer, and the structure was at length completed. It is 138 feet high, curving inwards from a basis of of 42 feet. It contains stories or apartments in height. More than 4000 tons of material were used in its construction. The lighting apparatus con sists of eight annular lenses revolving round a lamp of four concentric wicks, and producing every minute a bright blaze visible to a dis tance of 18 miles.
Among modern contrivances for lighthouses is that of forming the body of the building of iron. Such was the lighthouse constructed by Mr. Alexander Gordon, in 1842, for Ja maica ; and many others have since been made.
These structures are formed of cast-iron plates ar in some cases of sheet iron, riveted together and braced in various ways, and having pro vision made for the contraction and expansion of the metal. Mr. Bush for many years advo cated the use of a peculiar kind of floating Light or lighthouse on the Goodwin Sands, but after the expenditure of much time, money, and ingenuity, the project has failed. Another scheme due to Captain Bullock, has for its object the construction of a safety beacon on the same perilous locality ; and many other contrivances have been experimentally tried for the same purpose ; but we believe none of these well-meant schemes have shown indica tions of permanent success. One of the most remarkable of modern lighthouses or beacons is the screw-pile lighthouse of Mr. Mitchell. This lighthouse is constructed on spots where a sandy soil would render a fixed structure unavailable. It consists of a light timber edi fice, supported on eight or more very long and powerful piles, which are separately screwed down firmly in the sand by a screw formed at their lower extremity. One such lighthouse was constructed on the Maplin Sand at the mouth of the Thames, another at Fleetwood, and another at Carrickfergus. More recently, Dr. Potts has devised a mode of forming a foundation for a lighthouse on sand, by the sinking of hollow cylinders, through the aid of an air-pump, which pumps out the air from within the cylinder, so that the cylinder is forced down by atmospheric pressure.