moulds, or larva, of various shells; and emitting, when rubbed with steel, a bituminous smell, like that of the lapis suillus. The grit is cemented together by a calcareous paste; but the moulds of entrochi, vertebræ, &c. which the stone contains, resemble, in their composition, the hammites of Pliny; for the granules seem to unite only by the natural cohesive power of their surfaces. In some parts of the rocks are immense ammonita; and regular veins of chert, similar to those near Kimeridge, may be traced. The cavities of these rocks are the haunts of innumerable aquatic birds. "Whilst we were making our observations," observes the Doctor, "gulls, and a great variety of water fowl, fluttered over our heads. Amidst the screams and wild notes of these birds, the roar of the waves, the alpine aspect of the rocks, and the dusk of evening, there was a sort of gloomy grandeur that highly interested

us."

The old Castle, generally denominated Bow AND ARROW CASTLE, from its supposed appropriation to that mode of fighting, is at present only an inconsiderable ruin, containing scattered remnants of walls, and a portion of the keep. The rocks near it exhibit a truly bold and romantic appearance; and the edge of the cliff, to which probably the site of the original building extended, is awfully perpendicular. The erection of this fortress is commonly ascribed to William Rufus. In the year 1142, Robert, Earl of Gloucester, took possession of it for the Empress Matilda, which is the only historical anecdote that can be found respecting it. The walls are of a pentagonal form, perforated with a great number of loop-holes, and on every side, towards the land, are brackets, apparently for the purpose of leaving spaces, through which an enemy at the foot of the walls might be annoyed without exposing the besieged.

Near the Bill, on the south, and almost highest, part of the Isle, stand the Light-Houses. One of these was erected in the year 1716; the other as late as 1789. The upper, or Old House, contains two rows of Argand's lamps, furnished with metal reflectors, very highly polished. The lower, or New House, has six lamps of a similar construction, the light of which is increased by a lens

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a lens of twenty-two inches diameter. The lanterns of each house are glazed with the finest plate glass, fixed in copper frames. Every expence has been bestowed on the lights, to render them as good as possible; hence, in clear weather, it frequently happens, that they are visible till the distance is so great as to sink them below the horizon.

The New Light-House was built by William Johns, of Weymouth, at the expence of the Trinity Corporation. It has a grand and pleasing effect from the south; and, as a piece of architecture, is worthy remark. It is built of Portland stone, with pointed windows, and iron ballustrades round the top: the form is conical upon a circular plan, twenty feet in diameter at the base, and ten at the top, besides the cornice, which projects two feet. The height of the whole building, from the base, is sixty-three feet. In the inside is a geometrical stair-case, with stone steps, rail, and bannisters, which render it perfectly safe to ascend to the very curious apparatus fixed for containing the light. An inscription over the doorway commemorates the munificent founders, who are said to have erected this building "For the Direction and Comfort of Navigators, the Benefit and Security of Commerce, and a lasting Memorial of British Hospitality to all Nations." Its distance from the cliff is inscribed underneath. (1608 feet.) "I had often thought," says Dr. Maton, "that light-houses, and other buildings of the kind, which, from their very design, must be durable, might be used for ascertaining the changes on the coast in a certain series of years, and therefore made of eminent service to geology; and was much pleased to find this idea realized by the New Light-House in Portland." The very important service of these erections may be appreciated from the great danger of the adjacent coast. Innumerable masses of rock, just beneath the surface of the sea, extend in a south-west direction to a considerable distance off the coast, and eastward even as far as St. Adhelm's Head. In the former direction is a conflux of the tides from the French and English shores. These combined circumstances occa sion a very perilous surf, generally known by the name of the Race of Portland.

Not

Not far from the Light Houses is a remarkable Cavern, called Cave Hole, about fifty feet square, and twenty-one deep. Its shape is that of a dome perforated at the top, and reaching a good way within land. Through this aperture, in stormy weather, a large column of sea water is frequently forced up to the height of several feet. The inside is uncommonly grand and striking; and the effect is heightened by a ceaseless solemn roar of the waves. Some years since, a vessel from Cowes, of forty tons burthen, was driven into this cave; as are frequently small craft, whose sails may be seen through the hole. In the west part it branches into two caverns, whose extent it is said has never yet been ascertained.

The PORTLAND STONE QUARRIES are scattered, more or less, over every part of the Isle; but those of most repute are at Kingston. At this place is a pier, whence 6000 tons of stone, on an average, are supposed to be shipped off annually. From Mr. Smeaton's accurate description of these Quarries the following particulars are extracted.

"In the Quarries, the first stratum is one foot of blackish or reddish earth; then six feet of cap, or stone, but not fit for exportation. Below this is the bed of good stone, ten or twelve feet deep; and beneath it, flint or clay. In some parts an irregular vein of flint runs through it. Under the good vein there is no more good stone. The stratum of stone that is wrought for sale, lies nearly parallel with the upper surface of the Island, and with not much cover of earth or rubbish upon it. There are several beds of stone lying in contiguity one above another, varying in thickness, in general from two to four feet and upwards. Those which are usually called the merchantable beds, (on account of the blocks for sale being produced therefrom,) are universally covered with a stratum called the cap, which is formed entirely of a great variety of kinds, but in general so distinct and separate in their forms, that, to the curious naturalist, their species seem very easy to be made out; but as they in a considerable degree retain their respective figures, (though in some places more, some less,) spaces or cavities are left between them, which consequently very much diminish the coherence of the mass; but yet the cementing principle

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principle is so strong, that the whole together is considerably har der than the merchantable beds; and, indeed, so hard, that, to get rid of it as easily as possible, it is generally blasted off with gunpowder: were it not for these cavities, the cap-stone would not readily be worked with tools; or, at least, it would not be worth working at a place where there is so great plenty of stone of a better quality; but as it is necessary to remove it in the course of working the better kind of stone, though by far the greatest proportion is blasted in fragments, yet, for the buildings on the Island, the cap-stone is in general use, and also for the piers and quay walls of Weymouth harbour; and for several rough purposes under water, the cap would make quite as good and durable work as the merchantable blocks.

"When the merchantable beds are cleared of the cap, the quarry men proceed to cross-cut the large flats, which are laid bare with wedges in the way I have described as to the moorstone; only the wedges are not so numerous; nor does Portland stone split so evenly as the granite; and frequently in the splitting, as well as other working, of this stone, oyster and other fossil shells are discovered in the solid substance of the merchantable stone. The beds being thus cut into distinct lumps, the quarry-man, with a tool called a kevel, which is at one end a hammer, and at the other an axe, whose edge is so short and narrow, that it approaches towards the shape of a pick, by a repetition of sturdy blows, soon reduces a piece of stone by his eye to the largest square figure which it will admit; and blocks are thus formed, from half a ton to six or eight tons weight, or upwards, if particularly bespoke.

"When I viewed the simple construction of their carriages, I could not but wonder, upon being told that such a very plain piece of machinery was all they had for getting the largest blocks down to the water-side; but when I saw the application, my wonder ceased. I have already observed, that the plane upon. which the quarries are situated, is considerably elevated above the sea. It is further to be observed, that, though the greatest part of the circumference of the Isle to seaward is bounded by cliffs almost perpendicular, yet on the north side, towards the main land

of

of Dorsetshire, the descent is more moderate; though it is rather quick every where. It did not, indeed, at once occur to me, that, though it would require very great power to draw large stones against gravity, or up hill, and even a considerable one to draw them upon the plain ground; yet, in moving down hill, their gravity would assist them. The carriages are a sort of carts, consisting of nothing more than a pair of very low strong wheels, (as well as I remember,) about a yard in diameter, and a very thick axle-tree, upon which is fixed a stout planking, or platform, that terminates in a draught-tree, for steerage, and yoking the cattle to.

"The wheels and platform being low, the blocks are the more easily loaded thereon; and a necessary power is employed, according to the size of the block, to draw it to the commencement of the descent. To this place a quantity of blocks of different sizes have been at leisure times previously drawn; and one of these blocks, of a suitable size, such as experience has pointed out, is by a strong chain attached to the carriage on which the other block is placed, which is then drawn forward by the block in tow, till they are got sufficiently on the slope of the road to find an inclination in the loaded carriage to move the attached block; after which the horses and beasts of draught are taken off, except such as are absolutely necessary for the guidance; and in this way (the descent being continual to the pier) two large stones are got down with a degree of ease and expedition that would be almost impracticable with one alone, without more complicated machinery. About 9000 tons of stone are supposed to be dug in these quarries yearly."*

Though

*Portland stone was brought into repute in the reign of James the First, who employed it, by the advice of his architects, in the construction of the Banqueting House at White-Hall. After the fire of London, it was generally used by Sir Christopher Wren, in erecting the various public edifices; St. Paul's Church, the Monument, and, in fact, almost every fabric of note being built with it. Dr. Maton observes, that the name of Free-stone is very expressive of the useful property of the Portland-stone, in enduring to be cut in any direction, whether horizontal, perpendicular, or parallel, to the site of the strata; while it bears the injuries of the weather equally well in every position.