feet in length, by two hundred and thirty in breadth; and in this low state of the tides, its average perpendicular height above the surface of the sea is about four feet. Beyond the space included in these measurements, at very low tides, a reef extends about a thousand feet in a southwest direction, from the higher part of the rock just described; and on this reef the light-house is erected.

In the erection of a light-house on the Bell Rock, independently of its distance from the main land, a serious difficulty presented itself, arising from the greater depth of water at which it was necessary to carry on the operations, than in the case of the Eddystone light-house, described above, or of any other building of the same kind, ancient or modern, which had been hitherto undertaken. Its description is as follows:

The Bell Rock Light-house, which has not improperly, been termed the Scottish Pharos, is a circular building, the foundation stone of which is nearly on a level with the surface of the sea at low water of ordinary spring tides; and, consequently, at high-water of these tides the building is immersed to the height of about fifteen feet. The first two, or lowest courses of the masonry, are imbedded, or sunk into the rock, and the stones of all the courses are curiously dovetailed and joined with each other, forming one connected mass from the centre to the circumference. The successive courses of the work are also attached to each other by joggles of stone; and, to prevent the stones from being lifted up by the force of the sea, while the work was in progress, each stone of the solid part of the building had two holes bored through it, entering six inches into the course immediately below, into which oaken tree-nails, two inches in diameter, were driven, after Mr. Smeaton's plan at the Eddystone Light-house. The cement used at the Bell Rock, like that at the latter, was a mixture of puzzolano, earth, lime, and sand, in equal parts, by measure.

The stones employed in this surprising structure weigh from two tons to half a ton each. The ground course measures forty-two feet in diameter, and the building diminishes as it rises to the top, where the parapet wall of the light-room has a diameter of thirteen feet only. It is solid from the ground course to the height of thirty feet, where the entry door is placed, the ascent to which is by a

kind of rope-ladder, with wooden steps, hung out at ebbtide, and taken into the building again when the water covers the rock; but strangers to this sort of climbing are taken up in a kind of chair, by a small moveable crane projected from the door, from which a narrow passage leads to a stone staircase thirteen feet in height. Here the walls are seven feet thick; but they gradually diminish from the top of the staircase to the parapet wall of the light-room, where they measure one foot only in thickness. The upper part of the building is divided into six apartments for the use of the light-house keepers, and for containing the light-house stores. The lower, or first of these floors, contains the water-tanks, fuel, and other bulky articles; the second, the oil-cisterns, glass, and other light-room stores; the third is occupied as a kitchen; the fourth is the bedroom; the fifth, the library, or stranger's room; and the upper apartment forms the light-room. The floors of the several apartments are of stone, and the communication from the one to the other is effected by wooden ladders, except in the case of the light-room, where every article being fire-proof, the steps are made of iron. In each of the three lower apartments are two windows; but the upper rooms have four windows each. The casements of the windows are double, and are glazed with plate-glass, having besides an outer storm-shutter, or dead-light, of timber, to defend the glass from the waves and spray of the sea. The parapet wall of the light-room is six feet in height, and has a door leading out to the balcony, or walk, formed by the cornice round the upper part of the building, which is surrounded by a cast-iron rail, curiously wrought like net-work. This rail reposes on batts of brass, and has a massive coping, or top-rail, of the same metal.

The light-room was, with the whole of its apparatus, framed and prepared at Edinburgh. It is of an octagonal figure, measuring twelve feet across, and fifteen feet in height, formed with cast-iron sashes, or window-frames, glazed with large plates of polished glass, measuring about two feet six inches, by two feet three, and the fourth of an inch in thickness. It is covered with a dome roof of copper, terminating in a large gilt ball, with a vent-hole in the top.

The light is very powerful, and is readily seen at the dis

It

tance of seven leagues, when the atmosphere is clear. is from oil, with Argand burners, placed in the focus of sil ver plated reflectors, measuring two feet over the lips, the silver surface being hollowed, or wrought to the parabolic curve. To the end that this splendid light may be the more easily distinguished from all the other lights on the coast, the reflectors are ranged on a frame with four faces, or sides, which, by a train of machinery, is made to revolve on a perpendicular axis once in six minutes. Between the ob

server and the reflectors, on two opposite sides of the revolving frame, shades of red glass are interposed in such a manner, that, during each entire revolution of the reflectors, two appearances, distinctly differing from each other, are produced: one is the common bright light familiar to all; but on the other, or shaded sides, the rays are tinged of a red colour. These red and bright lights, in the course of each revolution, alternate with intervals of darkness, which, in a very beautiful and simple manner, characterize this light.

As a farther warning to the mariner in foggy weather, two large bells, each weighing about twelve hundred, are tolled day and night by the same machinery which moves the lights. As these bells, in moderate weather, may be heard considerably beyond the limits of the rock, vessels, by this expedient, get warning to put about, and are thereby prevented from running on the rock in thick and hazy weather, a disaster to which ships might otherwise be liable, notwithstanding the erection of the light-house.

The establishment consists of a principle light-keeper, with three assistants, two of whom are constantly at the light-house, while the third is stationed at a tower erected at Arbroath, where he corresponds by signals with the light-keepers at the rock.

This stupendous undertaking is highly creditable to Mr. Stevenson, the engineer, and does honour to the age in which it has been produced. The lights were exhibited, for the first time, on the 1st of February, 1811.

STONEHENGE.

[See Plate, No. 60.}

THIS celebrated monument of antiquity stands in the middle of a flat area near the summit of a hill, six miles distant