Page:The Building News and Engineering Journal, Volume 22, 1872.djvu/47

 Jan. 12, 1872. or pier, but in any case the work must be from this point upwards. ———_—__<._____ DECORATIVE PROCESSES. GILDING. By an ExprerienceD WorKMAN. (Continued from page 6.) ILVER LEAF may be and is used for gilding on glass as before described in these pages. The silvering of glass proper for mirrors is an entirely different process, in which, in reality, no silver is used, and for poor The metal employed for the so- called silvering of looking-glass is mercury or quicksilver ; this latter name means living “silver,” and was given to this metal by the ancients, probably on account of the lively and vivid appearance it presents; and as which leaf gold or silver makes but a substitute. silver is shorter than quicksilver it is pro- bable that may account for the process being called silvering, being quicksilver in combina- tion with tin-foil, forming an amalgam of tin. Silver is also mixed with copper and other metals of a yellow colour, and of these an inferior gold-coloured leaf is manufactured and sold at about a third of the cost of gold leaf. Much of this kind of metal is used for the inferior kinds of japanners’ work, such as tea-trays, waiters, &c., &c., the ornaments of flowers being partly coloured with trans- parent blues, lakes, &c., which, when well varnished and stoved, stands well, and al- together results in an exceedingly high- coloured and attractive article to the class of customers it is intended to captivate. It will be understood that this metal will soon tarnish and will ultimately go black, except it is protected. A very large quantity of this metsl is also used in the manufacture of the so-called gold paper-hangings. Many methods have been tried, and much scientific knowledge has been brought to bear upon the subject, in order to give these mixtures of metals a permanent charac- ter ; but we are not aware that it has hitherto been successfully accomplished, except by covering it by a coating of varnish of some kind. Most respectable housekeepers will have had experience of the fleeting nature of the reputed gold on wall-papers ; in a com- paratively short space of time a change comes over their brilliancy, and they gradually begin to turn brown, then black, and the slightest trace of the metal will have vanished. Of course there are some papers manufactured on which the gilding is of so good a quality that it will stand out bright for a year or two, and there are also wall-papers made upon which the gilding is really pure gold-leaf, and it is only in this latter case that per- manency can be secured ; all else must share the fate of the commonest gilt paper in time, and become tarnished and black. If alacquer varnish could be by some means spread over the gilding on wall papers, we do not see why they should not be as permanent in their character as the German gilt mouldings, and we really are of opinion that this might be managed, and we are surprised that our paperhanging manufacturers have not yet accomplished what appears to us so simple a matter to do, and yet of so much importance. There can be no question but that it would pay, for if we could convince the public that ‘tthe gilt would not tarnish, they would not mind a few shillings extra in the cost of a room. We have still another metal, or rather mix- ture of metals, which is beaten ont in the form of leaf-gold, manufactured in Dutch- land, and hence called Dutch metal. This leaf is of so inferior a quality that it is never used for (so far as we are aware) any but temporary purposes, such as gilding laurel and other kinds of leaves, holly berries, &c., at Christmas and other festival times; its thickness and porousness, and evanescent character, and its essentially metallic look, close jointed, the real backing commencing THE BUILDING NEWS. condemning it ata glance. Much of it is, how- ever, used by scene painters for the high lights on scenery for pantomimes, and for this purpose it answers well, because the scenes being rolled upon the rollers, except for the short time occupied by the perform- ance, the air and light is thus prevented from coming into immediate contact with the metal, and thus its brilliancy is preserved for a much longer period; in these cases it will be evident that a great display may be made at a small cost, the metal costing little over one penny per book. Of gold powders and bronze powders for gilding purposes we have a great variety. In the manufacture of these the same amalgam of metals is used as for the various kinds of leaves for gilding before described; but the whole of them are ground toa fine powder,. levigated, and purified, some being ground and mixed with gum and other glutinous and mineral substances, as a medium for working and securing them when applied to the object to be decorated. Of this nature is the gold used in the potteries for the gilding of china and earthenware, &c. This latter is, of course, pure gold ground to a fine powder, and mixed with a vehicle, which enables the workman to use it with an ordinary sable or camel-hair pencil. After it is pencilled, the article is passed through the kiln, and then burnished. Other mixtures, again, are ground so fine that they can be used with a quill pen, and written with somewhat similar to ordinary writing-ink. These are sold under the name of gold-writing fluids. Some of them may, of course, be made with pure gold, but the majority of them are but a delusion and a snare. We come next to the well-known shell gold, so extensively used for illaminating purposes. ‘The best kind is, of course, made from pure gold, ground exceedingly fine, and mixed with gum and placed upon mussel-shells for convenience, and sold in this state; but this is too expensive for all purposes, conse- guently there are many mixtures of inferior metals in the market, at a much less cost, which are extensively used for ordinary purposes. But of all these metals in-the form of powder or fine dust, the bronze powders are the most used in the arts. The house decorator, the japanner, the ironmonger, the lithographer, and, in fact, wherever gold leaf is used, we shall find that bronze powder is also used; on tin, iron, wood, plaster, paper, vellum, and other substances it is equally applicable, its variety of colour from bright yellow through all the gradations of yellows, reds, greens, to purple, gives us a wide field for its application. Of course, the same ob- jection applies here as in the case of all the metals before described with the exception of gold—namely, that all of them will tarnish except kept covered from the light and atmo- sphere, or by being varnished or in a book, of which we purpose to speak. more fully when describing the methods of using both gold and bronze. Gilding means simply the covering of various substances with a thin coating of gold. This is effected in various ways and by various methods, necessitating, as a matter of course. a variety of processes, according to the nature of the article or thing to be gilt. There is, first, the gilding on metals by fire, called amalgam, which is effected by dissolving gold in aqua regia (nitro-muriatic acid), and another method, called by the Italians, ‘‘ olla spadaro” (after the manner of the sword cutler). This was effected by putting thick gold leaf on the part to be gilt ; it was then placed in a fire, which completed the unions between the two metals, and it was afterwards burnished. But in the gilding of metals the invention of electro-gilding has made a complete revolution, and there can be no doubt but that this system will ultimately supersede all other methods of gilding on metals. We would here throw out a suggestion which has occurred to us in connection with electro-gilding—namely, we 31 cannot see why a pattern or ornament (simi- lar in character to the old style called damas- cening) could not be either printed or pencil- led upon the articles to be plated, with a varnish or medium which would prevent the deposit of the electro silver or gold upon the parts which it covers, and which would be easily removed after the article has been electro-gilt. If this could be done a wide field would be opened up for its applica- tion, as, for instance, supposing an article was first plated with silver, and then a damascene pattern was put on the silver in the manner above described, and then the parts left uncovered were plated with gold, we should have a work of art of a very high class at a comparatively low cost, the pattern being gold upon silver, or vice versa. As to the practicability of the operation, we have no manner of doubt whatever, and, therefore, commend the hint to those whom it may concern. Bookbinding is an art in which much gilding is used as a means of decoration, and although not coming imme- diately under the category of house decora- tion, still few houses are considered as com- pletely finished without decorated books, and, therefore, we may notice briefly the manner in which books are gilt. In the present day bookbinding is divided into different branches, and the backs of books are gene- rally made by a manufacturer who attends specially to that branch, so that a publisher can order and have made say athousand backs, but need not have them all bound up at once, but only as he may require them, and so it has gradually come to pass that what had formerly used to be done by hand, by tooling, is now done principally by machinery. The progress made in the art of embossing has greatly facilitated the decoration of books, inasmuch as the whole of the letters, orna- ments, and embossing, whether gilt or left plain, can be, and is performed, at one and the same time; the leaf gold is previously laid upon the parts to be gilt, it is then stamped with steel dies and letters, and the superfluous gold is then brushed off. In this case no mordant is used for securing the gold, the pressure alone being sufficient to fasten it to the cloth or leather. Seine PLUMBING.—I. (esas are few things in connection with 5 our modern houses of greater interest, so far as the comfort and health of the tenants or inmates are concerned, than the character of the plumber work. The ramifica- tions of the pipes in thousands of cases are now so many and various, and the eyil effects of bad work and of bad planning are so often manifested upon those exposed to their bane- ful influences, that it becomes a question of the highest importance to all concerned—and who is not ?—What is the character and con- dition of the plumber work? In answer to this question, and in order to throw some light upon the subject, it is our intention in the following articles to give such information upon the matter as, we trust, may be both useful and interesting to all. If we allow the mind to dwell for amoment upon the subject of architecture in stone, three glorious eras rise up before us, in which the genius of the Egyptian, the Greek, and our own Medieval ancestors had scope and produced such grand effects, all in consonance with the wants and aspirations of their several ages, and effects, too, which it is yet left for the future to excel. It is different, however, with plumbing, for in no past age have its present productions as a whole either been equalled or surpassed. Of course the mind here may revert to the vast works of the Romans, &c., in connection with their water supply, but apart from other considerations, a distinction must be drawn between engi- neering and plumbing. ‘The present is the era and grand opportunity of plumbing, and in order to bring it to perfection both the archi- tectiand the plumber must workin harmony,and