rate it at the both part only, but this is the least quantity that can be assumed, the mercury being supposed to give off one-half its volume of ammonia; and he is now inclined to think it may contain theth of new matter on the antiphlogistic theory, and about th ou the phlogistic theory. The professor concludes this part of his subject by observing, that though the researches on the decomposition and composition of nitrogen, have produced only negative results, yet he conceives that they may not be devoid of useful applications. It does not scem improbable that the pas sage of steam over hot manganese, may be applied to the manufacture of nitrous acid: and there is reason to believe that the ignition of charcoal and potash, and their exposure to water, may be advan tageously applied to the production of volatile alkali, in countries where fuel cheap. (To be concluded in our next.) MONTHLY RETROSPECT OF THE FINE ARTS. The Use of all New Prints, Communications of Articles of Intelligence, &c. are requested under COVER to the Cure of the Publisher. Mr. Landseer's Observations on the Plan of the A Chalcographic Society. FEW months ago, the writer of the monthly Retrospect in this Magazine, thought it necessary to speak in praise of a plan submitted to the public for improving the art of engraving in England by the Chalcographic Society; and neither the ill-natured remarks of Mr. Landseer thereon, a re-consideration of both pamphlets, his own commendatory article, nor the patronage the scheme has received, induces him to alter his opinion. The circumstances that led to Mr. Landseer's ill-tempered letter on this praise-worthy society, and bis illiberal, ungentlemanly, abuse of some of its members, are briefly as follows, and which are here inserted in support of the former observations offered on the published plan of the Chalcographic Society. Mr. Landseer was proposed, at his own request, to be a member of the society, and rejected at the ballot. In the spleen of his disappointment, he published the pamphlet now under consideration. Its object appears, from the title-page, to be fair observations on the plan; but its real objects are the excitement of mistrust and disunion between the members of the Society for the Encouragement of the Art of Engraving," and those of the Chalcographic Society;" to thwart the views of the latter by misrepresentation and calumny; and to distract the former in the exercise of their patronage, by a confusion of doubts and scruples. The letter (for so it is called, although no name is given to whom it is addressed) is a curious specimen of absurdity, spleen, malignity, and, we might say, falsehood; for we in vain look for the "view of im proving their scheme of patronage," which the title-page promises; and we are Essays of the London Architectural Society This is the second volume of essays by a Society of gentlemen, who have incor rated themselves for the mutual study and and improvement of this branch of the Fine Arts. The first essay is by the president, (Joseph Woods, jun. F.L.S.) on modern theories of Taste, and is rather a review of Allison, Burke, Price, and Knight's theories, than an original project. The author combats some, and argues ably on others, of the ingenious, but too fine.drawn, speculations of modern theorists. This essay adds considerably to the general stock on this undefined, and perhaps undefinable, feeling; but it is not so closely applied to architecture, as might have been expected from a professor in the art. The second essay is by Mr. Savage, (vice-president), on Bridge-building, and displays much knowledge of the subject, and sound reasoning. The theories of Dr. Hutton, Mr. Att wood, and the Encyclopædists (in Dr. Rees's edition) are carefully and ably examined, and their defects boldly pointed out. Mr. Savage, as might be expected from a practical architect, (which Dr. Hutton expressly declares his treatise not to be written with the feelings of) gives examples as well as precept; but, as only part of his essay is printed in this volume, a close investis, gation of the author's principles must be deferred till its conclusion. The next and. last essay is on Foundations, by Mr. James Elmes, (vice-president), in which this fundamental branch of architective skill,, as practised by the greatest architects, is brought to the test of practice, and as boldly condemned where he considers, then erroneous. This is a practice that deserves commendation, and should be oftener done; for great names often Countenance great errors. Of the inten-, tion and contents of this highly-useful essay, Mr. Eles shall speak for himself in the following quotation. 66 Having thus quoted the opinions of some archi tects, whose practical and theoretical knowledge have procured them the just distinction of masters in the science, I shall proceed in the first section of the following essay, (by way of summary,) to collect them to a focus, which I shall denominate the Ancient Practice. In the second, to narrate my own method in common cases, detailing some difficulties that have occurred, with the methods used to overcome them, and the event of their success. And in the third, a compendium of rules drawn from the above sources, which I shall fcall the Modern English Practice of forming Foundations." These investigations the author has executed with conMONTHLY MAG, No. 206. siderable ability; and, as the conclusions› are the result of practice, there can be no hesitation in recommending it to the attention of the profession at large. D. The Architectural Antiquities of Great Britain, displayed in a Series of Engravings, with an bistorical and descriptive Account of each Subject. By fobn Britton, F.S.A. Part II. No. IV. of Vol. III. Langman and Co. Taylor, and the Author. This is the fourth Number of the third volume of this very useful work, both to the architect and the antiquary. The plans are architecturally faithful, and the views at once scientific, useful, and picturesque. This Number contains seven engravings, from St. George's Chapel, Windsor, viz. 1. A View of Beauchamp's Monument, &c. 2. Fine Specimens of Groining, &c. 3. Groinings over the organ screen to the Great Western Window. 4. The Great Western Window. 5. Fitzwilliam's Monument. 6. South-west view of the Chapel. 7. Interior View of the North-aisle: which last is one of the most beautiful specimens of perspective engraving, particularly the distance, which has appeared for a long time, and reflects great credit on Mr. II. Le Keux, the engraver. INTELLIGENCE. The Arts have sustained another loss of an able son, and the Royal Academy. of a worthy member, in Mr. Zoffanij, who "shuffled off his mortal coil" in the beginning of last month. Johann Zoffanij, esq. R.A. (sometimes called Sir Johann Zoffanij) portrait and historical painter, was born at Frankfort; and arrived in England to study the arts, about the year 1764, and suffered much from po verty and want of encouragement; from which state he was rescued by lord Bar- rington, whose portrait he painted... Shortly after this he visited Italy, with recommendations from his Majesty to the grand duke of Tuscany; and while at Florence, he painted his celebrated picture of the Florence Gallery. He afterwards returned to England, which he left for India, where he received much encouragement; and has of late lived in privacy. The style of Zoffanij's works, are truth of expression, a fine deep tone of colour, and high finishing in the detail. His principal works are portraits of dramatic performers of the time of Gar rick, King, Shuter, &c.; a picture embracing portraits of all the members of the Royal Academy; a similar one of the Royal Family, &c. 3 L On On Monday, the 19th ult. Mr. Carlisle commenced his course of anatomical lectures at the Royal Academy, which shall be noticed in our next; as shall be the Rev. Mr. Foster's new Number of his elegant selection from the works of the best masters; and we are glad to see MR. I that he has included Sir Joshua Rey. molds among the old masters, who can not possibly suffer by the connexion. At the annual meeting of the Royal Academy, on the 5th ult. Mr. G. Are nald, landscape painter, was elected Associate. PATENTS LATELY ENROLLED. MICHAEL SHANNON'S, (BERWICKSTREET, LONDON,) for Improvements in the Art of Brewing. N the specification, giving an account of these improvements, we have out Ined drawings exhibiting representations of the machinery, seen on diferent sides. From the lower part of the copper is a communication, through a cock and pipe, into a box or chamber from which there are five communications, viz. one through a cock to empty it; another to the bottom of the infusing vessel to draw off the contents; another to the top of the infusing vessel; one with a pump, worked by the first mover; and another with the air vessel, which keeps up a constant re-action when required. The infusing vessel may be made of different forms and materials, but it is recommended, by way of prefer ence, that it should be cylindrical, and of wood, and it is to be provided with two faise bottoms, or perforated partitions, one near each extremity, for the purpose of allowing the liquor or wort to pass more freely into and out of the same, during the time of operating. The process is described as follows: Malt is put into the infusing vessel, which in most cases may be filled, or nearly filled, with the same, excepting between the false bottoms or perforated partitions and the end thereof, and the water is to be put in due quantity into the boiler, and heat applied as usual. When the water is sutliciently hot, it is to be so applied by means of the cocks and pipes above described, that it will rise through the malt to the level in the boiler; but it would not pass through if it were not for the pump, which is, at the same time, to be worked by any adequate and convenient first mover, and it draws the water through a lower valve; and, at its returning stroke, forces it through an upper valve, placed within the receptacle on each end of the barrel. By this action the hot water is forced gradually through the malt in a constant stream, the air escaping through a pipe, which returns through the boiler by means of the cock and pipe, and by this meant the wort is kept hot, and repeatedly pas sed through the grain until the strength of the malt is entirely extracted. And whenever it may be found necessary and expedient to cause the water, liquor, of wort, to pass down the infusing vessel instead of upwards, it will then be only necessary that one set of cocks should be shut, and another set opened, and in that situation the heated water will be forced up the pipe, and downwards through the vessel; out of which it will pass into the boiler, by a reverse operation; in this case, it will he needful to keep the cock shut, until the infusing vessel is filled with liquor. By these improvements, the wort may be made as strong as the pro portions of materials will allow; the inconvenient and imperfect operation of mashing is avoided, and the sprout, or exhausted grain, may be afterwards drawn out with great facility and saving of labour. A like apparatus may be applied for passing the wort through hops, instead of boiling, in case the same should be preferred, either for purposes of economy, or giving a peculiar strength or difference of flavour to the liquor by this method. MR. CHARLES WILLIAMS'S, GRAVEL-LANE, LONDON,) for a Machine for Grinding Malt, &c. The machine, or mill, used on this occasion, is composed of a cylindrical or conical roller, made of cast-iron, or any other metal, with grooves cut in it in an oblique or parallel direction: this roller acts against loose knives, made of har dened steel, and screwed together so as to form the same curve as the roller. These loose knives, or cutters, may be taken out and ground, or sharpened, at pleasure. In the margin of Mr. Williams's specification, is a drawing of the elevation of the mill. The roller is put in motion by a steain-engine, or any other power; which roller acts against the knives or cutters, fixed in a parallel di rection rection with the roller. The malt, or other substance, to be ground, passes between the rollers and the cutters. There is an adjusting screw to keep the roller at a proper distance from the knives. There are two levers that act against the brasses of the bearing of the roller, and keep the roller up to its work. A farther use of these levers, is to admit and allow the roller to rise up, when any thing gets between it and the knives, that by its hardness might injure the one or the other, and let it pass through; the roller will then fall into its former station. There are Weights made to slide on the levers, so that they may be adjusted, and more weight not permitted to act against the roller than is sufficient to keep it to its work. The roller and are worked upon a carriage, which carriage may be made of divers forms. Besides the figure already described, there are others exhibiting the spindle, to which the moving-power is to be applied; the sliding brasses for the ruller to work in; the double-wired screen, to take the rubbish and dust from the malt, or other matter. The upper wire is coarse enough to let the malt, or other matter, through, and the bottom one to take out the dust. There is a beater fixed on the screen to act against projections on the roller, to give motion to the screen to shake the malt, or other matter: there is also a spout to clear the top screen of the rubbish, and a hopper fixed at the top of the screen, in which is put a wire to take out the thickest of the rubbish. cutters MR. STEPHEN HOOper's, (walworth,) for a Thermometer for ascertaining the Heat of Bakers' Ovens, and various other purposes. The principle of this instrument consists in the comparative degree of expansion, or contraction, which takes place in different substances, when these sub. stances are exposed to different degrees of temperature; and, in order to reduce this to practice, the instrument is constructed as follows, which we shall give in the patentee's own words: "I make use of two rods, bars, o tubes, of any convenient length and shape; and the substances of which these rods are made are such, that one of them is subject to a greater degree of expansion or contraction than the other, when exposed to different degrees of temperature; or, in other words, I chuse such substances, that one of them may be subject to as little, and the other as much, variation in length as possible, when heated or cooled; posses sing at the same time such other properties as render them of convenient appli cation. I do, therefore, generally make use of brass and wooden rods, or, as being more convenient, a brass tube and wooden rod, which are hereinafter more particularly described as follows: that is to say, I make a brass tube of any con.. venient length and diameter. The length of the said tube I generally make equal to the length of the oven to which the thermometer is intended to be applied, and about an inch and a quarter in diameter. Into the said brass tube Lintro. duce a wooden rod, made of fir, or any other very straight-grained wood; the wooden rod being nearly of the same length as the brass tube, and of such a diameter as to slide freely backward and. forward in the brass tube without sticking. The said brass tube and wooden, rod, are firmly fixed to each other at one' end, so that if any expansion or contraction arising from a change of temperature, takes place in the brass tube, that change of temperature will be indicated at the other end by the increase or decrease of the length of the brass tube, when compared with that of the wooden rod, the said rod having a scale fixed thereon for that purpose. But as the divisions upon the said scale, when so contracted, are too minute to be easily made, or distinctly observed, I prefer a scale with larger divisions, which I obtain by applying a lever, or a combina tion of levers, according to the wellknown methods now in use for constructing pyrometers, or by a rack and pinion; in which case I affix a rack to the end of the brass tube, and cause the said rack to turn a small pinion; and upon the axis of the said pinion I place a hand, or index, which points the degree of expan sign or heat upon a circular plate, properly divided. The said pinion and plate, in which the axis of the pinion turns, are affixed to the wooden rod.” Mr. Hooper next describes the mode of using his thermometer, when applied to bakers' ovens: that is, he causes a channel, or hole, to be made in the brickwork, about six inches below, and parallel with the bottom of the oven, extending from the mouth to the farther side of it, in such a direction as that a vertical plane passing through the channel, would nearly bisect the oven door. The instru ment ment is introduced into this hole, leaving the index end exposed to view below the door of the oven; the channel may, however, be made in any other convenient part of the oven. MR. MAVER OPPENHEIM'S, (LONDON,) for a Red Transparent Glass. The nature of this invention may be thus described: We are directed to take of the materials that compound the fintglass, to purify them, and to add to them an equal quantity of brann-stein, or braun-stein, a species, we presume, of manganese ore; mix them well together, and place them in a reverberatory furnace for thirty-six hours, when the calcination will be completed. This calcination must be cohobated, or repeatedly exposed to the action of warm water, till no saline particles remain, when it may be dried, and an equal quantity of sal ammoniac put to it; and it is then to be levigated, or reduced to powder, by the help of distilled vinegar. It is now to be dried and put into a retort, well secured, placed in a sand furnace, and exposed eighteen hours to a fire sufficiently strong for sublimation; after this, the calx is to be separated from the sublimed matter. To this sublimate, an equal quantity of sal-ammoniac is to be added, and again levigated in the same manner as before directed. The mixture is to be brought back into the retort, and a fire applied that shall be strong enough to convert the braun-stein to a liquid. Of this liquid, half an ounce is to be taken, and to this thirty grains of dissolved Dutch gold are to be added. This quantity is to be mixed with every pound of the flint materials, and the mixture being placed in a reverberatory furnace, there will be produced a white flint glass, which, on a second exposure to the same heat, will be red and transparent. The above-named compounds of the flint-glass, contain two parts of lead, one part of sand, and one part of saltpetre or borax, VARIETIES, LITERARY AND PHILOSOPHICAL. Including Notices of Works in Hand, Domestic and Foreign. Authentic Communications for this Article will always be thankfully received, DR R. DRAKE will shortly publish, in four vols. 8vo. under the title of the Gleaner, a selection of the best essays from those periodical papers which have not been included in the last edition of the British Essayists. It will be elegantly printed on demy, and on royal paper, to match with the recent 8vo. editions of the Tatler, Spectator, and Guardian; and will afterwards be reprinted uniform with the British Essayists. A Life of the late Arthur Murphy, esq. by JESSE FOOT, esq. his executor, is in the press. It will form a quarto voJume, and contain the Epistolary Correspondence of Mr. Murphy with many distinguished persons, during a period of more than fifty years, An Account of the Isle of Man, comprising its history, antiquities, and present state, from the pen of Mr. GEORGE WOODS, will be ready for publication in a few weeks. The History of Lynn, civil, commercial, biographical, political, and military, from the earliest accounts to the present time, by WILLIAM RICHARDS, A. M. will shortly be completed in one large 8vo. volume. Mr. MARRAT'S work on Mechanics, will make its appearance in the course of the present month. Mr. CHITTY, of the Middle Temple, has announced his intention of delivering immediately after Michaelmas Term, a practical course of Lectures on Com mercial Law. This series will compre hend dissertations from the best writers on the Lex Mercatoria among nations, as acknowledged by our municipal law; on the commercial privileges and dis abilities of aliens; on the modes adopted by the different branches of the British législature for the promotion and regu lation of foreign and domestic commerce; and on the spirit and effect of all the various mercantile contracts. The object of these lectures is not only to assist, by their practical utility, the different members of the legal profession, but also to arrange these extensive and important branches of the British Constitution in a clear and comprehensive point of view, for the information of those gentlemen who may be preparing to embark either in commercial pursuits, or in the public service of their country. The lectures will be delivered twice a week, in the evenings of Monday and Thursday, in Lincoln's Inn Hall, which the Honourable Society |