Specification of the above Screw Pile Light-house, erected on the north-eastern low water spit of North Wharf Bank, at the entrance of the Wyre Navigation, the structure being supported upon, and secured to, the bank with Mitchell's Patent Screw Piles of three feet diameter.

The foundation of the building is formed of seven screw piles, six of which are the angles of a hexagon, about 46 feet in diameter, and the seventh pile stands in the centre of the figure.

The heads of all the outer piles have an inclination inwards, by which the diameter of the frame work connecting the top of the columns, and upon which the house stands, is contracted to about 27 ft. Each screw pile is formed of a malleable iron shaft 15 ft. long, and 5 ins. diameter.

On each pile a 3 foot screw is firmly keyed near its lower extremity, beneath which is placed a large drill, or opening, bit.

At the upper end of the shaft is a screw of 18 ins. long, and 2 ins. diameter, for drawing down and screwing the wooden column to the iron pile, which latter stands about 5 ft. out of the ground.

The columns are thus prepared,-seven logs of Baltic timber are selected, of the largest and best quality; the centre one is 56 feet in length, all the others are 46.

The pedestals rise about a third of their height, and the remainder of the shafts are rounded, both for appearance and as lessening any vibration from the action of the sea.

An opening in the lower end of each column is then made of 5 ins. diameter, and to the depth of about S feet, by boring in the manner of a water pipe; strong iron hoops are then driven upon it, hot, the first about 8 feet up, the second about 4 feet, and the third at its lower extremity.

This hooping will give to the column greater strength than it originally possessed, especially as the wood removed by boring is the weakest in the tree, and adds scarcely any thing to its actual strength.

The column being raised perpendicularly above the iron pile, the end of the latter is introduced into the opening prepared for it, and which has been made to fit accurately upon it; when the top of the pile has reached the end of the cavity, screwing on (by capstan,) the foot of the column will be inserted in the bank about 3 feet; the wood, when wet, will clasp firmly on the iron, but, as an additional security, the internal screw attaches the two together.

The framing upon which the house stands is firmly secured round the centre column, and to the heads of the outer ones, by means of cast-iron capitals let down over the heads of the columns, the capitals being cast hollow for the purpose; to the abacus of these the top framing is secured with screw bolts passing down through the wood and iron, having nuts on the under side, all boring, or cutting, into the main support of the building being thus avoided, and the adjacent parts of the framing are bound together by wrought-iron straps and knees; the beams which radiate from the centre to the heads of the outer columns are 12 ins. deep by 7 ins. wide, and those which connect the head of the outer columns 12 ins. by 4.

To give lateral strength to the building to resist the effect of heavy bodies drifting against it, twenty-four angle braces from round iron of 14 inch diameter are applied, as shown in the plan, by which a resisting power equal, at least, to 350 tons, is presented in every direction; these braces are secured at the top to trusses cast with the capitals, and beneath to strong wrought-iron bands with projecting bolt holes; by these means boring into the columns is again avoided; the braces are keyed up at their crossing, as shown in the plan.

The light-keepers' house, which is hexagonal, is in diameter from angle to angle 22 feet, and 9 feet in height.

The centre column rises to the base of the lantern, which, with the roof, it assists to support, giving great additional stability to the whole

structure.

The corner posts of the house are 7 ins. by 6, all remaining studs 6 ins. by 4, beams of roof 9 ins. by 5, and all outside planking, together with floor and roof of house, is 2 ins. thick.

The house has an outside door and three windows, and is divided into two apartments, one having a fire place and the floor tiled; the walls and ceiling of both apartments are lathed and stuccoed.

The lantern, which is 12 sided, is 10 feet in diameter, and in height to the top of the windows 8 feet, by which the lights are raised above the highest spring tide level about 31 feet, or 444 above half tide level.

The lights (in this case of dioptric order) show throughout the periphery, and the roof is covered with strong sheet iron, (a lightning repeller and conductor, of course.)

The light-keepers' house is covered with sheet-lead, and a light iron railing is carried round the top of the building and the platform. London, Jan. 31, 1840. HENRY MANGLES DENHAM.

Explanation of Plate II-A, marl formation; the screws are 10 feet below low water mark; B, sub-stratum of sand; C, low water equinoctial springs; D, low water ordinary tides, 2 feet above ditto; E, low water neap tides, 9 feet above ditto; F, half tide level, 15 feet above ditto; G, high water neaps, 21 feet above ditto; H, high water ordinary tides, 28 feet above ditto; J, high water equinoctial springs, 30 feet above ditto; K, underside of platform, 45 feet above ditto; centre of the dioptric light in lantern, 60 feet above ditto.

Ibid.

On the Pyramids of Egypt.* By J. J. SCOLES, Esq., F.R.I.B.A. About three years since the two first parts of the magnificent work of Colonel Vyse, on the Pyramids of Egypt, were presented to the Institute, and Mr. Scoles then read a paper on the subject of the discoveries made by Colonel Vyse, and described the pyramids at Ghizeh. On the presentation of the concluding number of the work, he took the opportunity, on the last meeting of the Institute, to resume the subject, and to describe the further discoveries which have been made * Read at the Royal Institute of British Architects. .

in the pyramids situated at Sakkarah, Dashhour, and other places in the "Faioum;" and which are delineated in the third number from drawings by Mr. Perring, the civil engineer, under whose direction the various excavations were made at the expense of the gallant Colonel.

There appear to be thirty-nine pyramids in Middle and Lower Egypt, all of which have been explored by Mr. Perring. They are situate on the western side of the Nile, chiefly on the desert hills, occupying a space, measuring from north to south, of fifty-three English miles.

The first pyramid described by Col. Vyse, is known by the name of Abou Roash; the base is 320 ft. square. The bulk of it is built of the mountain rock, (a sort of hard chalk) which has been reduced to a level around it, and the defective places have been made good with masonry. No part of the external casing is to be found; indeed, the edifice was not probably ever completed, or raised to a considerable height. A passage about 160 ft. long, commencing on the north, and descending at an angle of 22° 35', leads to an apartment about 40 ft. by 15 ft.; above it smaller chambers appear to have been constructed similar to those in the king's chamber in the great pyramid of Ghizeh, called "Chambers of Construction," because they relieve the lower part from the superincumbent weight. Near to the pyramid are heaps of broken granite, which may be the chips of the blocks for the extreme casing; the blocks themselves, probably, have been re-used in modern times, as the pyramids have been a sort of quarry for ages. past. The fragments, though granite, crumble to pieces upon being handled, and are much decomposed, either from great antiquity, or from an exposure, not merely to the corroding air of the desert, but also to the moist winds of the Delta. The common saying, that it never rains in Egypt, only applies to the upper country. In the Delta, extending from the sea to the district of the pyramids, rain is frequent and copious, and it was noticed that persons have arrived at Alexandria, and remained there some time, subject to continual rain, and have left with the impression that it always rained in Egypt, although their idea before visiting the country was, that there it never rained.

The next pyramid is situate at Rhegah. Mr. Scoles here remarked that the names given to the pyramids, and by which they are known, are derived from the villages nearest these monuments, and have no reference to their ancient names, though frequently the site of an ancient city is to be traced in the modern name of the villages in the vicinity. This pyramid of Rhegah is curious, on account of being carried up in two inclines, like a pyramid at Dashhour. Mr. Perring did not succeed in discovering any entrance to it; but in the course of his excavation he discovered fragments of stone sculptured and colored, and some marked with golden stars upon a dark blue ground, as if belonging to the ceiling of an apartment.

At Abouseer are five pyramids, some tolerably perfect; Mr. Perring experienced great difficulty in exploring the interiors, as large masses of rubble masonry constantly fell in, and seriously injured