account of Dr Kirwan's anemometer will be found in the Transactions of the Royal Irish Academy for 1808. A new musical instrument, called the Clavi-cylinder, has been invented by the celebrated M. Chladni, who has already distinguished himself by his valuable work on the subject of acoustics. The Imperial Conservatory of Music at Paris have drawn up afavourable report of this invention, which they describe as resembling the flute and clarinette in high notes, and the bassoon in the lower keys; they observe, however, that it is more adapted for solemn music than for lively strains. According to Chladni's own description, the clavi-cylinder contains a set of keys, and behind this a glass cylinder, seven centimeters in diameter, which is turned by means of a pedal and a loaded wheel. This cylinder is not the sounding body, but it produces the sound by friction on the interior mechanism. The sounds may be prolonged at pleasure, with all the shades of crescendo and diminuendo, in proportion as the pressure on the keys is increased or diminished. This instrument is never out of tune; it contains four octaves and a half, from ut, the lowest in the harpsichord, up to fa. A new kind of oil, called oil of cabbage-seed, has been manufactured by M. Francois du Salingre of Halverstadt, from the seeds of the brassica, campestris, or cabbage plant. It is said to equal, in point of purity and yellow colour, the finest oil of Provence; it is inodorous, and has a taste of almonds, which distinguishes it from the oil of rape-seed; it may be substituted for olive oil in sallads, and when used as lamp oil, it gives a bright flame without smoke. Mr William Skrimshire has proposed to substitute, instead of coffee, the seeds of the Iris pseudacorus flower de luce, or common yellow. water flag, a British plant, which grows in great abundance in some marshes, and by the sides of ditches and rivers. The seeds may be obtain ed in great abundance, and when deposited in a dry place, will keep well for a long time. When they are roasted in the same manner as coffee, they resemble it much in colour and flavour, but have rather more of a sac charine odour, approaching to that of the extract of liquorice. Though the fresh root is a very powerful ca thartic, yet the seeds of the plant are completely destitute of this property. The aroma of these seeds may be preserved in the greatest perfection by roasting them in the husks. M. Blavier has discovered that some ferruginous rocks may be successfully employed as substitutes for emery. The rock which he conceives best fitted for the purpose of polishing metals, marbles, granites, &c. is the micaceous iron ore, which occurs in the hollows and on the summit of the granitic table land, between the left bank of the Aveyron and the Viaur. Its colour is sometimes grey, at others of a deeper or lighter red, but in either case its fracture is steel grained. These ferruginous rocks exist in the hollows in rounded nodules and in masses, the weight of which sometimes amounts to upwarde of 1 cwt. ; after the rock was pounded, and the coarser emery extracted, the last deposit of the washing would yield a substance capable of supply ing the place of the red oxide of iron, for the last polish given to me tals and even glass. By repeating the washings, this powder may be reduced to any degree of fineness. See the Journal des Mines, No. 111, page 201. A new machine, called the Pyreolophorus, which is wrought by the force of air suddenly expanded by heat, has been invented by Messrs Lenieps, and approved by the class of the Sciences of the National Institute of France. This machine is said to have carried up the Soane, with a velocity of double that of the stream, a boat loaded with five quintals, and presenting to the water a prow of the area of six square feet: In another experiment, the pressure exerted on a piston of three square inches was in equilibrio with one ounce, while the fuel consumed was only six grains. It appears from another part of the description, that the stroke of the piston takes up five seconds, so that the six grains were the fuel consumed in that time. ces up We have in our possession a drawing of a machine of this kind, which was invented by an ingenious artisan of this country before any account of Messrs Lenieps' invention was received here. The air is driven by a forcing pump into a vessel analogous to the boiler of a steam-engine, where it is heated and discharged into a steam-cylinder. The heated air for the piston, and operates exactly like steam, with this difference only, that the air, after having spent its force, is allowed to escape through a pipe carried up the chimney. The ingenious author of this contrivance has constructed a small working model of the machine; but it affords us no ground for believing that it will ever be substituted for the steam-engine, except in cases where water cannot be obtained. We should not be surprised to see the explosive force of gun-powder employed as the first mover of machinery. A method of purifying camphor, by means of potash, has been lately proposed and successfully practised. Two drams of camphor, with considerable empyreumatic smell and dirty, were mixed with one of olive oil and eight of sand, after which 20 grains of pure potash were added, and heat applied; but though it was greater than was necessary for its sublimation, the product was perfectly free from empyreumatic smell, and a little whiter than it generally is. A guage or measure for standing timber has been invented by Mr James Broad of Downing-street. The instrument is composed of two straight pieces of well-seasoned deal, about 13 feet long, joined together by a pin going through them. A little way from the larger end, is a brass arch, called the index, on which are engraven figures, denoting the quarter girth in feet and inches. In using this instrument, it is only necessary to take hold of the large end, and apply the other to that part of the tree where the girth is required, the instrument being opened so wide as just to touch at the same time both sides of the tree without straining it; the girth will be shewn after allowing for the bark, by the inner edge of the brass on the right-hand leg. A drawing and description of this instrument will be found in the Transactions of the Society of Arts, vol. xxv. An improvement on tram-plates for carriages on rail-roads has been invented by Mr Charles le Caan. As we cannot easily convey to our readers an account of this invention, we must refer them to the Transactions of the Society of Arts, vol. xxv. A method of rendering common alum as good for dyeing as Roman alum, has been discovered by M. Seguin, corresponding member of the National Institute. In order to free it from the iron which it contains, he dissolves 16 parts of common alum, and 24 parts of water, crystallises, and thus obtains 14 parts of alum equal to the Roman, and two nearly equal to that of Liege. This process might be employed in the manufacture of the alum, so as to obtain at first an alum worth one-third more than in its impure state. A new method of measuring a ship's rate of sailing has been proposed by James Burney, Esq. A line towing astern of a vessel which is passing through the water, will evidently pull against her head-way, and as the ship's way increases or decreases, the pull of the line will also increase or decrease. Mr Burney therefore proposes, that a line of about 20 fathoms should be passed through a pully, so as to go clear out at the stern-port or cabin window, while the inner end of the line is fastened to a loose chain of sufficient weight, on the deck under the pully, or to a number of small weights made consecutive by short intervals of line. Hence, when the ship sails, the chain or weights will be drawn up more or less according to the ship's velocity. It appeared from a trial made with about 20 fathoms of line rather larger than log line, the inner end of which was fastened to a spring steel-yard, that the strength of the pull varied with the rate of sailing. When the boat moved at about 24 and 5 knots an hour, the pull of the line upon the steelyard was observed to be equal from 24 to 54 lbs., a variation sufficient for the construction of a scale. Instead of measuring the variable resistance of the water by the compression of a spring, it would certainly be preferable to attach the inner end of the line to a long cylinder immersed almost wholly in a vertical tube filled with water. When the velocity of the vessel increases, this cylindrical weight will rise from the fluid till the additional weight which it thus gains becomes a balance to the increasing resistance of the water. In this case, the length of the scale may be exi dently varied at pleasure by employ ing different weights. M. Le Normand has invented a method of making excellent copal varnish without colour. In order to select the copal, each piece must be tried by letting fall on it a single drop of very pure essential oil of rosemary, not altered by keeping. Those pieces which soften at the part that imbibes the oil are fit for ma king the varnish, and the others are to be rejected. The pieces of copal are then to be powdered, and the powder sifted through a fine hairsieve, and put into a glass, on the bottom of which it must not lie more than half an inch thick. Essence of rosemary being poured upon it to the height of half an inch, and the whole stirred together with a stick for a few minutes, the copal will dissolve into a viscous substance, and the whole will form a very thick fluid. Let it now stand for a couple of hours, after which pour on gently two or three drops of very pure alcohol, which you will distribute over the oily mass, by inclining the glass in different directions with a very get tle motion. In this way their incor poration will be effected. Repeat this operation by little and little, till the varnish is reduced to a proper degree of fluidity. The first drops of alcohol are the most difficult, and require the longest time to incorpo rate; but the difficulty diminishes as each successive addition is incorpo rated, or as the mass approaches the state of saturation. When the va nish has attained the suitable degree of fluidity, it is suffered to stand a few days, and when it has become very clear, the varnish is to be decanted off. This varnish is made without heat, is very clear and colourless, may be applied with equal success on pasteboard, wood, and metals, and may be worked and polished with care, indeed better than any known varnish. It may be used on paintings, and singularly heightens their beauty. A new process for making a beautiful lake colour has been discovered by a German chemist. On a quantity of cochineal pour twice its weight of alcohol, and as much distilled water. The mixture being in fused for some days near a gentle fire, and then filtered, add a few drops of solution of tin, and a red precipitate will be formed. Continue two hours to add a little solution of tin till the whole of the colouring matter is precipitated, and then edulcorate the precipitate by washing it in a large quantity of distilled water. When the precipitate is dry, it is then ready for use. The aloe, which has hitherto been considered only as a medical plant, has been recently applied to many useful purposes. In the East Indies its juice has been employed as a varnish to preserve wood, and even the skins of living animals, from the attacks of worms and insects. An aquatic solution of hepatic aloes has been found of great service to naturalists in preserving young plants from insects, and dead animals and vegetables from putrefaction. According to Perner, a simple decoction of aloes communicates to wood a fine brown colour. M. Fabroni of Florence has extracted a beautiful violet colour from the juice of the fresh leaves of the aloe: exposed by degrees to the air, this colour resists the acids and the alkalies. At first the liquid becomes red, and at the end of a certain period turns to a beautiful purple violet, which adheres to silk by simple immersion without the aid of acids. M. Degen, a watch-maker of Vienna, is said to have invented a machine by which a person may rise in the air. This contrivance consists of two parachutes of taffeta, which may be folded up or extended at pleasure, and the person who guides them is placed in the centre. M. Dagen is said to have risen by means of this machine to the height of 54 feet, in presence of numerous spectators in Vienna. This invention has directed the attention of some of our own countrymen to the construction of a machine for the same purpose. An account of their labours will be found in our next volume for 1810. An instrument for throwing light into the interior of the animal body is announced in several of the foreign journals, as the invention of M. Bozzini. It is said to be composed of a recipient, containing the light of tubes for conveying the rays to the cavi ties which are to be enlightened, and of reflecting tubes for the purpose of transmitting the luminous rays to the eye of the observer. We are disposed to think, that if such a machine has been constructed, it cannot possibly answer the object of its inventor. A new method of preparing the extract of opium, without any of that smell for which it is distinguished, has been successfully employed by M. Parmentier. Twenty-four ounces of opium being macerated for five days in rain water, boil it for a quarter of an hour with 2lbs. of pulverised charcoal, and after it is strain ed and clarified with the white of an egg, 12 ounces of extract will be obtained after suitable evaporation. A new travelling carriage, which forms a complete habitation, has been invented by M. Franconi. It consists of a body 15 feet long, 74 wide, and 6 high, elevated 3 feet from the ground upon the wheels of a common curricle. Racks are placed upon the four sides capable of feeding 16 or 20 horses, and the canvas which covers the carriage when in motion may be raised as a pavilion for the purpose of sheltering the horses. The interior of the machine is divided by a partition into two apartments, and there is a gallery in front, to which the traveller can go with out alighting. Four horses are only necessary for travelling post with this carriage. A new and simple method of filtering water has been applied on a large scale by M. Alexandre, for purifying the waters of the Garonne. It consists in merely conveying the fluid through the capillary tubes of a piece of half-worn-out cotton, which will allow the fluid to pass in a state of extreme limpidity. The pyrolignous acid obtained from the distillation of wood has been applied, by M. Vitalis, to the dyeing of thread and cotton, and the process has been introduced into all the manufactories of Rouen, where black cottons for mourning, which were formerly procured from Holland, are now dyed in a cheap and substantial manner. The colour lasts very long, and is not liable, like common blacks, opticians of the present age. The division of the instrument is accom plished by ocular inspection. The usual tools for graduating are not employed, and the whole operation is so contrived that no error can take place, but what is chargeable to vi sion, when aided by the best optical instruments for viewing and measu ring the most minute quantities. As we cannot convey to our readers a proper idea of this valuable invention, we must refer them to the Philos. Trans. for 1809, in which it is fully explained by its author. A very simple, though a very great improvement in the construc tion of forcing frames for hot-beds has been made by T. A. Knight, Esq. In the common method the surface of the bed is made horizontal, but, to give some degree of eleva tion to the glass, the north end of the frame is made nearly twice as deep as the other, so that if the mould was, as it ought to be, of the same depth over the whole bed, the plant would be too far removed from the glass at one end of the frame, and want room at the other end. To remove this inconvenience, Mr Knight proposes to place the hot-bed on an inclined plane of earth raised about 15 degrees, making the surface of the dung and mould parallel with it, and accommodating the shape of the frame to the surface of the bed. By this means, the plants on the mould of the hot-bed are more exposed to the rays of the sun, while the ex pence of the forcing frame is diminished. Mr Knight has used with great success a hot-bed of this de scription for forcing grapes. He pla ces the bed three feet from the wall, to which the vines are trained, and introduces their branches into the frame through holes made at the |