Notices to Correspondents. TO OUR READERS.-We intend to devote a portion of the Wrapper of each Number for a List of Artisans, &c., who require situations. We shall only charge the Advertisement Duty for each insertion. Those parties who wish to dispose of their Inventions or Improvements, will find that the DECORATOR'S ASSISTANT will afford an excellent medium for advertising, and the Manufacturer also, as the circulation of the Work will be chiefly among those actively engaged in Engineering and other works. PREVENTION OF EXPLOSION IN POWDER- vivid positive picture makes its appearance; MAGAZINES. An important discovery, the and all the fixing these photographic picresults of which are likely to prove of the tures require is, well washing in pure water. highest importance, has recently been com--Builder. municated by M. Probert in a memoir to the Paris Academy of Science. It consists in a simple but certain means of preventing the explosion of powder-magazines, a catastrophe which has so repeatedly been productive of the destruction of buildings and loss of human life. By the new process, the powder, whilst in the magazine, may be deprived of its explosive power, which, when desired, may be almost instantaneously restored. For this purpose it is sufficient to mix the granulated powder (the only sort that is explosive) with the fine powder or dust obtained in its manufacture. This mixture, so easily made, fuses without explosion or detonation, and may, in this state, be safely stored in the magazine. To use the powder thus preserved, it is sufficient for the artilleryman to sift it through a sieve properly constructed for the purpose. Probert has found that pulverised saltpetre A. B. C.-The following hints may be useful to you as to the may be efficaciously substituted for the powder dust; and that in either case the powder thus treated is less subject to damage from the effects of damp or from other causes of deterioration. An experiment, so easy of proof, ought, we think, to be made in some one of the arsenals of this country; and, if it should be found effective in preventing the lamentable effects of sudden explosion, we would earnestly recommend the adoption of so simple and economical a process in every depôt, magazine, and powder-manufactory throughout the kingdom. M. PHOTOGRAPHIC PICTURES.-NEW PROCESS.At a recent meeting of the Western Literary and Scientific Institution, a lecture on the chemical influences of the solar rays was delivered by Mr. Robert Hunt. The imme. diate subject of the lecture was the phenomena of "photography as exhibited in the Daguerreotype, and the numerous sensitive processes now employed for obtaining representations of natural objects by means of the camera-obscura; and also by the more simple method of copying by direct radiation. Among the most interesting of the photographic processes described as being the most simple and certain, was the chromatype, discovered by the lecturer. It consists in washing good letter-paper with the following solu tion: *** We shall be happy to oblige any Correspondent with any information he may desire to possess. Letters to be prepaid, and addressed to the "Editor of the DECORATOR'S ASSISTANT," 17, Holywell street, Strand. colours that may be compounded with the best effect for imitating in drawings the different woods, metals, cloths, &c. used in the various articles of cabinet furniture, stating the principal colours first. To imitate MahoganyMix light red with burnt umber; shadow with burnt umber. Rose Wood-Mix lake and lamp-black; shadow with a stronger tint of the same while wet. Satin Wood-Use yellow ochre; shadow with Vandyke brown." Bronze-Mix Prussian blue, gamboge, and burnt umber; shadow with Vandyke brown and indigo mixed. BrassUse gamboge; shadow with burnt terra de Sienna, and stipple with burnt umber; inlaid brass or buhl ornaments may be laid on afterwards with a body colour made of gamboge and flake white. Or-Molu-Mix king's yellow and Indian yellow. Velvet-Mix carmine and Indian red. Green Baize-Mix indigo and gamboge; for chair seats, use vermilion. Glass-Mix lamp-black and indigo; shadow with the same. Porphyry Marble-Mix lake, Venetian red, and ivory black; afterwards speckle with constant white and with lamp-black. Verd Antique-Mix indigo and Roman ochre; afterwards lay on light and dark green spots. We shall continue these hints next week. AN AMATEUR. 27 ft. in. 117yds. 26ft. Therefore the base, according to the above dimensions, would contain nearly 118 cubic yards. Mention the sizes of the cases, or cisterns, and we will reply to your queries. Respecting the paint, we will probably answer you next week. A CONSTANT READER.-The "First Steps to Geometry" will be followed by "Outlines of Perspective." Z.-The design for a shop-front, in No. 4, was original, the work of a well-known architect. The first Monthly Part of the DECORATOR'S ASSISTANT, in a handsome illustrated wrapper, is now ready. Price 7d. MAGAZINE, 17, Holywell-street, Strand (where all communications to the Editor are to be addressed); and to be had of all Booksellers.-Saturday, June 26, 1847. London: Published at the Office of the SPORTSMAN'S Printed by W. COOLE, Lumley Court, Strand. fast on the decline; and that the English Empediments to Art in England. artisan may speedily become as celebrated for the tastefulness of his patterns and ornamental designs, as he is, undoubtedly, beyond competition for the solidity of his material, the intelligence of his manipulation, and the workmanlike superiority of his productive skill. Beauty of Form. Among the sources of enjoyment which Nature has presented to us, is beauty of form. "The highest beauty of form," says Sir J. Reynolds, "must be taken from Nature; but it is an art of long deduction and experience to know how to find it. We must not content ourselves with merely admiring and relishing; we must enter into the principles on which the work is wrought; these do not swim on the superficies, and, consequently, are not open to superficial observation." Our conceptions of beauty of form, or of any kind, can never exceed that of the objects from which, in every degree, our ideas and sensations of beauty are derived. By this I mean, that as all our ideas of beauty are derived from a contemplation of the works of Nature, our perceptions can never exceed the beauty of her perfect works. As amongst them man stands pre-eminently conspicuous for the beauty of his form, the human figure, both as a whole and in its parts, should, therefore, stand as the model and the test of the beautiful of form.-From J. D. Harding's splendid work, entitled "The Principles and Practice of Art." No one, I think, will doubt the material world to have been constructed and adapted to the animal wants and gratifications of man; and it is equally unquestionable that it has been so IRECTLY and bene-ordered as to contribute in like manner to his ficially as the in- need of mental enjoyments; and that he, in fluence of a culti- his turn, has been so "curiously made," as to vated taste and cor- feel naturally urged in search of the gratificarectness in design tion provided for him, and which he receives must, on all hands, be allowed in proportion as he prepares himself for it. to bear on the countless productions of our manufacturing skill, it is, comparatively, but of late years, that anything approaching to a systematic effort has been attempted in this country with a view to fostering the obviously natural connection which should ever exist between art and artisans. Confessedly unrivalled in the excellence of construction and material, our workmen, whether from attachment to the prescribed uniformity of a dull routine, and consequent aversion to change, or from whatever progress-restricting motive, would seem to have regarded the superaddition of refined embellishment in the light of a needless extravagance, or, at best, but as an adjunct of merely secondary importance. Hence the decided inferiority of most of our objects of manufacture, destined either as ornamental to the person, as in the case of articles of dress, or for the decoration of the interior of dwellings, as, for instance, the materials for paper-hanging. A striking, and, we fear, by no means isolated illustration of this indisposition of the English artisan to de- INGENIOUS INVENTION FOR DRIVING PILES.part from the beaten path made familiar to him Dr. Potts, of Buckingham-street, Adelphi, by habit long confirmed, is officially furnished has lately invented a method of driving piles, in the Parliamentary Report on the subject for which he has taken out a patent, and which of Artisans' Schools of Design. A French de- is calculated to prove an immense improvesigner of paper-hangings, lately came over to ment in the construction of piers, embankestablish a manufactory in this country. He ments, breakwaters, and other similar strucemployed English workmen to paint his de- tures. The main feature of the invention is signs, and insisted that the tints should exactly the substitution of pneumatic power for manual correspond with his drawings. But the work-labour. Hollow tubes are employed, which men at once struck work: they had been accustomed to make up their tints in large quantities-had never used but three greens, two reds, or two yellows-and so on; and it was considered by them as absurd to submit to the caprice of a Frenchman who seemed to think that there were as many colours as days in the year. The concern was, consequently, broken up. (Vide Mr. Dyce's Report to the Board of Trade on Foreign Schools of Design.) Let us hope, however, that a similar feeling is now No. 7.-VOL. I. may be formed of any material, and almost of any shape. The lower extremity of the pile is quite open, and it is placed upon the bank or ground, whether composed of sand, shingle, mud, clay, bog, or other material, either plastic or miscible with water, under the surface of which it may be rendered available to a great depth. From the tube or hollow pile the air is extracted by pumps, and as matter rises through the interior of the tube, the latter makes a corresponding descent. Remarks on London Street Wouses and Shop Fronts. This the neighbourhood of London, this curve of the frieze has been copied to a nicety, even where the space open to the builder was unconfined on every side? absurd practice, created in ignorance, and truding on the adjoining property. fostered by servile imitation, has become generally prevalent in shop fronts over the whole of London; nay, it has even intruded THOUGH We have no wish to see measures itself upon the untutored taste of the country generally adopted, by the directors of a city, carpenter: for can it be believed that, in the that would trench upon the liberties of indi-door-pieces of some cottages lately erected in viduals, yet in many cases it becomes necessary for the public good to do so. The inhabitants of the northern metropolis seem to have been aware of this, when they agreed upon the measure of confining the feuars, or builders, to a certain description of front elevation in the erection of their shops and other street houses. For the New Town of Edinburgh, an architect, under the direction of the Dean of Guild Court, furnished the street elevations to the builders; and, in whatever way the interior of the houses might be disposed, the exterior was not allowed to be altered in any way, not even an inch either in height or width, in the foundation of pillars or windows, from that prescribed, without the special sanction of that court. Hence the uniformity of the streets of Edinburgh, and of the houses in them. These general elevations are for the most part supplied with good taste; the buildings situated at the corners of streets and turnings have an additional story, and in the centre of each line is a large house, with a pediment in front, or some other imposing feature, to harmonise with the additional stories or attics of the extreme houses. In London, on the contrary, with very few exceptions, this practice has been but little followed; and no one, with any pretensions to taste, can walk along the principal streets in the English metropolis, without feeling dissatisfied with the irregularity of the buildings. In passing along Oxford-street, we see such a variety of tastes displayed in the erection of the houses (as diversified as the faces of the individuals who inhabit them); such different heights and widths of the buildings; such unequal heights and widths of openings; and such a variety of inconsistent ornaments, of which no human being can trace the origin; and, in short, such masses of inharmonious, heterogeneous combinations, that one is led to think that each successive builder must have been blind to all around him, except his own building, during its erection, inasmuch as it forms no part of a whole with the adjoining structures. Although each building may be uniform in its parts, and form a whole in itself, its want of association with the buildings near it, which claim an equal share of notice, at once renders its combinations with such buildings inharmonious, and offers no alternation of predominant and subservient features, without which no objects can satisfy the eye. But the most absurd architectural objects that present themselves in this city, a city famed for possessing individuals of the highest talents and purest taste, are the shop fronts. As all objects that have for their fundamental principles regularity and uniformity must influence individuals, and, consequently, affect society (for even the inmates of a dwelling in which the domestic arrangements are neat and orderly are exemplifications of this fact); and as no field of study offers easier access to individuals than architecture, being open to all, and even intruding itself upon our notice, so ought it to be the business of those who have influence, not to permit such bad taste to descend from generation to generation, but to employ every means in their power to disseminate good taste, or, at least, that sort of taste which is considered good by men of acknowledged talent. This would be a public benefit in the end, and ought to interest every individual. To forward this object, it would be well that no house whatever should be built without an elevation being furnished by some proper person; and, even if this were supplied free of expense to the parties about to build, it would be a positive benefit to the country in the end. It may be said that, if the general elevations of streets were furnished by one individual, as in Edinburgh, it would prevent the emulative spirit of proprietors and builders, and, perhaps, produce monotony in the appearance of the streets; and further, that the various productions of different minds must be preferable to anything that can be produced by one individual. To meet these objections, it would be necessary to have various architects employed, each to furnish the elevations of the street houses for his own particular district; and, before any building was begun, the elevations respectively should be approved of by a majority of the architects thus appointed. This would insure variety, and create competition for fame among the professional persons employed, who would each endeavour to make our streets surpass those of every other town or city, in point of beauty. With regard to the improvement of shop fronts, or rather, the abolition of the curve in the frieze of the architrave over them, we should remark, that in all cases where practicable, the pilasters ought to be kept far enough within the limits of the frontage of the building (even should doing so reduce the width of the windows) to admit of the proper projection being given to the cornice, without introducing the curve in the frieze. But even In composing the dressings of the shop if the columns or pilasters are brought out to fronts in many streets, but especially in the extent of the premises on which they are Oxford-street, it is customary to hollow out used, the cornice may be finished, in a very the frieze like a scotia, in order to give the consistent and handsome manner, against a cornice its proper projection, without in-block, supported by consols or trusses. There are a few shop fronts in London finished in this manner, and great credit is due to the architects who have designed them. We hope that the foregoing few hints may create a desire to effect an improvement in objects of such importance and such interest as the London street houses and shop fronts. Process for Gilding the Wheelwork of Watches, Chronometers, &c. is to be gilt with a layer of verdigris, and the amalgamation of the surface goes on very rapidly. To apply the gold, the wheels are to be removed from the mercurial solution, and surrounded, without being cleaned, with the amalgam of gold. This being done, they are to be heated upon a little drum of sheet iron, the upper surface of which is pierced, to admit of the pinion being inserted, thus permitting the convenient application of heat to that portion of the wheel which has been gilt, without the pinion itself being sensibly heated, or its temper altered. This little sheet-iron drum is heated on its under side by a spiritlamp. THE improvements which are sought, day by day, to be introduced in the construction of accurate timekeepers, with the view of mak- The solution of mercury, which serves the ing them more accurate and more elegant, purpose of amalgamation, produces, when dehave seemed to indicate the necessity of composed by heat, only water, nitrous oxide, gilding the wheels of accurate watches. It is nitrogen, and mercury, results which do not probable that this beautiful process, which, on exercise any action upon the pinions of the account of the safeguard against dirt which it wheels, at the temperature at which the operaoffers, must tend to promote the precision of a tion is carried on. By means of a wire brush, watch, would have been put in requisition long that peculiar grain may be given to the brass sooner if the known processes of gilding had portion of the wheels which fashion has permitted of the task being executed; but rendered necessary. The wheel is lastly hitherto the mercurial gilding process (electric cleaned in soap and water, the pinion regilding was out of the question) has consisted maining as bright as it was before the operain operating on the metal to be gilded by tion. means of a solution of that metal in nitric acid, which would have completely destroyed the steel pinions of the wheels. To cover these pinions with a layer of wax or of resin would have been an impossibility, inasmuch as the resin would have been more or less destroyed by the action of the acid; and, moreover, it would have been very difficult to free these covered parts from the adherent protecting material. This means of solution, which enables the! maker to guard the wheels of chronometers when at sea from the corrosive action of the salt spray, may prove to be of utility in making the instruments more correct than they else would have been. Amongst the examples which I submit to the inspection of the academy are found-first, the ungilt wheels which have served up to the present day; secondly, a specimen of wheels gilt by my process; thirdly, wheels coloured red, which, after having been gilt by the foregoing process, have had a colour imparted to them by a method a long time known, and which consists in boiling the wheel for the space of some minutes in a solution of carbonate of soda to which three or four drops of chloride of gold have been added, an operation which does not in any way affect the pinions. The very simple proceeding which I have the honour to communicate to the academy, and which obviates this inconvenience, consists in using, for the purpose of amalgamation, a solution of mercury, which neither acts upon steel, whether hot or cold, by the products of decomposition which it develops. In order to procure this liquor, a little mercury is dissolved in a slight excess of nitric acid, and the solution is now saturated with ammonia, and This reddish colour, which is more rich, and then the precipitate is dissolved in an excess which has been called into existence by the of that alkali. If the precipitate does not taste or caprice of the world, adds nothing to entirely dissolve, the liquid is to be filtered, the perfection of gilding. It is necessary only the residue redissolved in nitric acid, and to guard against employing solutions which supersaturated with ammonia, so that the new are too concentrated, and not to prolong precipitate may be dissolved. The ammoniacal beyond a certain time the ebullition, because nitrate of mercury, of which this precipitate is composed, scarcely dissolves in free ammonia, but is tolerably soluble in nitrate of ammonia, with which it forms a double salt that even crystallises tolerably well. Consequently it suffices to operate in such a manner that there shall be in the liquor a sufficient quantity 5 Mai, No. 18, 1847. of nitrate of ammonia to redissolve the precipitate. To amalgamate the wheels by means of this solution there is no precaution to be taken: they may be plunged altogether in the fluid, and allowed to remain there some minntes, without the pinions being in the slightest degree affected; the excess of ammonia rapidly covers the part of the wheels which then the pinions which are not desired to be gilt would otherwise undergo that operation, requiring a great expense of time and trouble to remove the golden covering and expose the steel.-Translated from the French of M. Philippe Plantamour, in the "Comptes Rendees," TO POLISH FURNITURE.-Melt together in a pipkin, half a pound of bees'-wax, and a quarter of an ounce of alkanet root, until the former be well coloured; then add linseed oil and spirits of turpentine, of each, half a gill. Strain through a piece of coarse muslin.Household Book of Practical Receipts. |