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1817.] ; and he will, no doubt, push these ingenious and interesting experiments much farther.—It appears that such earth will absorb the hundredth part of its weight of moisture without having its power sensibly impaired, and is even capable of absorbing as much as the tenth part, It can hence easily be made to freeze the eighth part of its weight of water, and might even repeat the process again. In hot countries, the powder will, after each process, recover its power by drying in the sun. Ice may therefore be procured in the tropical climates, and even at sea, with very little trouble, and no sort of risk or inconvenience.

In the Bath Literary and Philosophical Society, the Rev. Mr Wright has described a very ingenious method of working a ship's pump by mechanical means, when the crew are too few in number to attend to that duty, and particularly in a heavy gale. It was used by Capt. Leslie in June last, during a voyage from Stockholm to America, when the crew were exhausted with pumping, and the ship was sinking. He fixed a spar aloft, one end of which was ten or twelve feet above the top of his pumps, and the other extremity projected over the stern; to each end of the spar he fastened a block: he then fastened a rope to the apearsspears [sic] of his pump, and after passing it through both pulleys along the spar, dropped it into the sea astern: to this end he fastened a cask of 110 gallons measurement, and containing 60 or 70 gallons of water, which answered as a balance-weight: and the motion of the ship made the machinery work. When the stern of the ship descended, or any agitation of the water raised the cask, the pump-spears descended, and the contrary motion raised the spear, and the water flowed out. The ship was thus cleared in four hours.

At a meeting of the commissioners appointed to manage the yearly grant of £10,000, voted by Parliament for finishing the college of Edinburgh, the plan of Mr W. Playfair being adopted, the prize of 100 guineas was adjudged to that gentleman. According to Mr Playfair's plan, the exterior of the building, as originally planned by Adams, is to be retained with very little alteration; but there will be a total departure from the internal arrangements. The southern side of the quadrangle is to be occupied almost entirely by the library, which will be 190 feet long, and one of the most elegant rooms in the kingdom. The western side is to be appropriated to the museum, and the other two sides are to be occupied chiefly as class rooms.

A new mode of giving additional strength to iron and steel, is proposed by Mr Daniell. His plan is to twist metal in the same manner as strength and compactness are given to hemp and flax.

The trigonometrical survey of Great Britain, under the direction of the Ordnance Board, proceeds without interruption. The maps of three-fifths of England and Wales are already completed. In the course of the summer, the British surveyors are to be joined by two eminent French academicians, with a view of connecting the trigonometrical surveys of the two countries, and thus not only attaining a greater degree of geographical accuracy, but obtaining, perhaps, a more satisfactory solution of the problem respecting the true figure of the earth. The French gentlemen appointed to assist Colonel Mudge and Captain Colby are, M. Biot and M. Mathieu of the Institute of France, whose principal object is, to measure the length of the pendulum at Greenwich, Edinburgh, and the Orkneys.

A new and ingenious instrument, called the Colorigrade, has lately been constructed by M. Biot, for giving names to different colours, according to the place which they occupy in Newton's scale. By this means colours may be described accurately and scientifically.

A new species of resin from India, has been analysed by J. F. Daniell, Esq. F.R.S. It consists of It forms a very admirable varnish, which is not only highly transparent, but bears the heat of the warmest climate without cracking or changing colour.

Mr Pond, the astronomer royal, has discovered in the stars α Aquilæ α Lyræ, and α Cygni, a constant parallax of half a second; but he is disposed to ascribe it to some other cause than that of the ordinary parallax. Dr Brinkley of Dublin found the parallax to be two seconds.

A stone is said to have been lately found at Pompeii, on which the linear measures of the Romans are engraved.

The Congo sloop of war is arrived at Deptford. Several large cases, containing the natural productions of Africa, collected in the late expedition to the Congo, have been sent to Sir Joseph Banks, for the purpose of being assorted in their respective classes: many of them are of a kind hitherto unknown, and the whole will shortly be submitted to the inspection of the public.

Mr Murray has succeeded in fusing two emeralds into one uniform mass; also two sapphires into one, by the compressed mixture of the gaseous constituents of water in the oxihydrogen blow pipe.

Mr Locateli, the celebrated mathematician of Milan, has invented a new piece of mechanism (says a Paris paper), by means of which vessels may ascend rivers without the assistance of a steam-engine. The first experiment, which was made on a small boat, completely succeeded. The inventor asserts, that his plan is applicable even to a man of war, and that it will secure her from the danger of shipwreck. The strength of a single man, or at most that of a horse, is sufficient to put this machine in motion.