visit to a very ingenious gold-beater at Hamburg, he assured me that he prepared this substance himself, and that the case was the same with most of the gold-beaters in Germany. Even in England, in the year 1763, this art was known only to two or three persons, who practised it as a business, but kept it so secret that Lewis was not able to obtain a proper account of it. In Ireland also this skin is prepared and sent to England. When the French, in the beginning of the revolutionary was, hoped to out-manoeuvre the Germans by the use of aerostatic machines, it became of some importance to them to obtain a supply of these skins. On this account, the Commission des armes et poudres drew up instructions for preparing them, which they caused to be printed and distributed to all the butchers. At Strasburg they were printed in French, and at the same time in German, but in many parts faulty and unintelligible. About the year 1621, Mersenne excited general astonishment, when he showed that the Parisian gold-beaters could beat an ounce of gold into 1,600 leaves, which together covered a surface of 105 square feet. But in 1711, when the pellicles, discovered by the Germans, came to be used in Paris, Reaumur found that an ounce of gold, in the form of a cube, five and a quarter lines at most in length, breadth, and thickness, and which covered only a surface of about twenty-seven square lines, could be so extended by the gold-beaters as to cover a surface of more than one hundred and forty-six and a half-square feet. This extension, therefore, is nearly one half more than was possible about a century before. The art of gilding, and particularly unmetallic bodies, was much facilitated by the invention of oil-painting; but it must be acknowledged that the process employed by the ancients in cold-gilding was nearly the same as that used at present. Pliny says that gold leaves were applied to marble with a varnish, and to wood with a certain kind of cement, which he calls leucophoron. Without entering into any research respecting the minerals employed for this cement, one may readily conceive that it must have been a ferruginous ochre, or kind of bole, which is still used as a ground (poliment, assiette). But gilding of this kind must have suffered from dampness, though many specimens of it are still preserved. Some of the ancient artists, perhaps, may have employed resinous substances, on which water can produce very little effect. quicksilver, his gilding might have been considered as that with gold-leaf by means of heat, dorure en feuille à feu, in which the gold is laid upon the metal after it has been cleaned and heated, and strongly rubbed with bloodstone, or polished steel. Felibien was undoubtedly right when he regretted that the process of the ancients, the excellence of which is proved by remains of antiquity, has been lost. False gilding, that is, where thin leaves of a white metal such as tin or silver, are applied to the article to be gilded, and then rubbed over with a yellow transparent colour, through which the metallic splendour appears, is much older than I believed it to be in the year 1780. The process for this purpose is given by the monk Theophilus, whose fragments were first printed in 1781. According to his directions, tin beat into thin leaves was to be rendered of a golden yellow colour by a vinous tincture of saffron, so that other pigments could be applied over it. The varnish or solution of resin in spirit of wine or oil, used for this purpose at present, appears not then to have been known. But in the sixteenth century this art was very common; and instructions respecting it were given by Garzoni, Cardan, Caneparius, and others, in their writings. About the same period, a pewterer at Nuremberg, named Melchior Koch, was acquainted with the art of communicating a golden colour, in the like manner, to tin goblets and dishes. He died in 1567; and with him, as Dopplemayor says, the art was lost. A method of applying a white metal to paper, and then drawing over it a gold varnish, has been known in China since the earliest periods. At present this method of gilding is practised more in Sicily than in any other country. It appears also to have been used, at an early period, for gilding leather and leather tapestry; and this perhaps was first attempted at Messina, as we are told by John Matthæus, who, however, in another place, ascribes the invention to a saint of Lucca, named Cita. But gilt leather was made as early as the time of Lucian, who conjectures that Alexander, the impostor, had a piece of it bound round his thigh. The dress of the priests, on the festival of Bacchus, was perhaps of the same kind.-Abridged from Bohn's Edition of Beckmann's Inventions. EFFECTS OF FOUL AIR.-The purity of the air we breathe is quite as important as the That gold-leaf was affixed to metals by means wholesomeness of the food we eat. When air of quicksilver, with the assistance of heat, in is loaded with putrid gases, from decaying anithe time of Pliny, we are told by himself in mal and vegetable substances, it becomes an more places than one. The metal to be gilded actual poison. When the air is very foul was prepared by salts of every kind, and rub- indeed, it has been known, in some few instanbed with pumice-stone in order to clean it ces, to destroy life in an instant; and very thoroughly, and to render the surface a little often fatal disease is brought on by exposure to rough. This process is similar to that used at such air, even for a short time. But the present for gilding with amalgam, by means of general effect of impure air is the gradual heat, especially as amalgamation was known to diminution of health and strength, not prothe ancients. But, to speak the truth, Pliny ducing actual disease, but rather that tendency says nothing of heating the metal after the to disease which renders every sickness with gold is applied, or of evaporating the quick-which a person may be attacked, more severe silver, but of drying the cleaned metal before more unmanageable, and more frequently fatal. the gold is laid on. Had he not mentioned-Why are Towns Unhealthy? SHORT TIME ON SATURDAYS.-The following gentlemen have already given their consent to the proposition made by the carpenters and joiners of the metropolis-namely, Mr. Thos. Cubitt, Mr. William Cubitt, Mr. Baker, Mr. Kelk, Mr. Jackson, Mr. Piper, Messrs. Armstrong and Smith, Mr. Freak, Mr. Myers, Mr. Fitzpatrick, Mr. Lee, and Mr. Seth Smith. (See page 72, ante.) GOTHISM.-The magnificent altar-piece of St. Gudule's, at Brussels, designed by Rubens, has been disposed of to an Englishman, in order to save the expense of regilding, and has passed through a London auctioneer's sale-room! A. B From B as a centre, with any radius, describe the arc a c. From A, with the radius A B, cut the arc A c in D; and with the same radius from c cut it in E. Then through the intersections D and E draw the lines D B and FB, and they will trisect the angle, as was required. PROBLEM XIII. EXPERIMENTAL LODGING HOUSES IN GLAS On Fresco Painting. (Continued from page 78.) Qualities of Execution.-All the qualities pro- either been well washed and kept for a length White-i. e., lime, exclusively, which has of time, or rendered less caustic by boiling, repeated manipulations, and drying. Yellow-all kinds of ochres, terra di sienna. oxides of iron, and lake-coloured burnt vitriol. Red-ditto ochres, burnt terra di sienna,* Brown-umber, raw and burnt, and burnt terra vert. Black-burnt Cologne earth. Purple-burnt vitriol, cobalt blue, and lakecoloured burnt vitriol. GOW.-The experimental establishment, which has been fitted up by the "Glasgow Association for Establishing Lodging Houses for the Working Classes," comprises four stories, affording facilities for accommodating separately the single males, single females, and married couples, leaving the ground storey as a dieting department. It has accordingly been thus arranged, -the three upper floors as dormitories according to this classification, and the ground floor as a day-room, divided by low partitions into corresponding compartments for the use of the lodgers during the day, and in which they may take their meals. For economy of space, the dormitories have been fitted up with two tiers of berths, after the manner of passengers' cabins on ship-board, excepting that the upper and lower berths are entered from opposite sides; thus, though rendering more standing room necessary, accomplishing the complete separation which is essential in houses of this description. Each berth is furnished with a seat, and is enclosed by a door, in order to secure the clothes and other property of the occupants; and each dormitory is provided with a water-closet, also a lavatory containing several wash-hand boxes, so that a small number may wash at one time. The kitchen and bar are combined, and are situated at one end of the ground storey, separated only by a counter from the seated portion forming the day-room. Here are provided the means of furnishing plain wholesome meals; and advantage is taken of the draught in the furnace, which heats the coppers, for ventilating the dormitories above; this is effected by means of an upright shaft of tin tubing, which communicates with each floor, and leads into this furnace, so as to become mainly the source of its supply of air, while it is the medium by which the vitiated atmosphere of the several floors is drawn off downwards. In the present case the downward mode of ventilation happened to be the most available. Arrangements are being made for fitting up, in the rear of the premises one bath for male and another for different stages of the burning, produce very brilliant Cornelius says that the brightest particles, selected at female lodgers. Green-terra vert (or Verona green), cobalt green, and chrome green. Blue-ultramarine (pure and factitious). These colours are perfectly safe, have been well tested, and, for the most part, admit of being mixed in any manner. Chrome yellow and vermilion are also employed; but not, as yet, with complete suc cess. The lime destroys all animal and vegetable colours. tints on the palette; for, if they are mixed Great attention is requisite in preparing the during the work, the painting will appear "streaky" when dry. white was as follows, being precisely the same Cennini's mode of preparing the lime as a slaked lime, reduced to a white powder; place as that at present practised:-Take very white it in a large tub, and mix well with water, reds. The Art of Pottery. (Concluded from page 80.) pouring off the water as the lime settles, and adding fresh for eight days. The lime, divided into small cakes, is then placed to dry in the sun or on the housetop, and the longer these cakes are left the whiter they become. To shorten the process, the cakes may be In all nations, the earliest products of earthenmoistened again with water and well ground, ware may be described as coarse in textureand then dried. This operation, once or twice tender, that is, easily scratched, and very repeated, renders the lime perfectly white. brittle. The latter quality is not, however, Cennini observes that, without this finely-invariable. The earliest of the Etruscan vases ground white, flesh tints, and other mixed tones that may be required, cannot be executed in fresco. A corrrespondent of the Athenæum, some time back, stated that, "The sky-blue pigment used in the ancient Egyptian catacombs consists of a glass or fritt coloured by the black oxide of copper; and that the red found in the same catacombs consists of a similar substance coloured by the red oxide of copper." are entirely red or entirely black, without colour or ornament: the ansation, or system of handles, was so clearly derived from the human form, that hands and arms were sometimes directly introduced, and on cinerary urns the cover was frequently a bust of the deceased. The Etrurian, Italo-Grecian, and Egyptian vases present the most striking evidence of a common type; and in the most artistic of these productions the archetype has Mr. Buss, from whose lecture we have manifestly been the bust of a beautiful female. before quoted, says that, "The colours em- The Etrurians actually reproduce this model, ployed should be almost entirely of mineral-but the Egyptians recede from it widely. origin, carefully selected, well ground, and Like every other art, pottery must have kept in small pots with covers to them. Ultra- greatly advanced before efforts were made to marine is a difficult colour to manage, as it is combine beauty with utility; and it is quite in apt to fall off the pictures in the form of accordance with recorded experience, that the powder; to remedy this, the Italians usually first advance in artistic decoration should be painted this part in tempera, over a ground of founded on natural resemblances. The ancient black or red, or a mixture of both. Lake is vases found in Chili and Peru have the top not available in fresco, and it is supposed that and neck frequently formed into rude imitathe boasted colour called hæmatite, and by tions of the human shape; so, also have several other names, was, in reality, no nearer several of the Mexican jugs and cups in the to the quality of lake than Indian red, to judge Sèvres collection. Indeed, the similarity bealso from some English specimens which have tween the Greek and Peruvian vases is not been procured. Whatever may be the age of confined to general outline, but extends to the time, those colours which do not quickly minute details of ornamentation,-the wavy change upon a trial slab may be used." lines, the friezes, and even the truncated shafts, which have been usually regarded as the distinctive marks of Grecian art. (To be continued.) MANUFACTURE OF BRONZE IN PARIS.-In colour and casting the Parisian Fabricants de Bronze have arrived at a great pitch of perfection. Their methods of obtaining the former, depend on peculiar processes, both in the first and final operations. They restore the fire colour with wonderful success, and they produce a great variation in tints, from the peculiar green bronze, to the richest depth of a golden brown. This must have struck everyone who has visited the different collections. As far as it is dependent on the casting, namely, on the proportions of the materials entering into the composition of the bronze, we have gathered, that the metal is generally made up of the following:-Copper, 82; zinc, 18; pewter, 3; lead, 14. It should be understood, however, that the bronze here indicated is such as is intended for "gilding." If in the bronze there be too much copper, it takes more gold; if too much zinc, the fine yellow in the gilding colour is lost. For great monuments, such as the "Column of July," it is composed of copper, 91 40: zinc, 5'53; pewter, 1.70; lead, 1-37; total, 100.-The bronze industry of Paris occupies abour 6,000 workmen; viz., 400 sculptors or modellers, 800 founders, 600 turners, 1,800 mounters, 600 gilders, silverers, and varnishers, 1,200 engravers or chisellers (ciseleurs), and 600 labourers, It is of some importance to direct attention to the imperfection of the evidence on which it has been attempted to found a complete distinction between the Etruscan and the Grecian vases. Truth appears to lie between the extreme theories of Micali and Raoul-Rochette. We may concede to the former that there was a native school of Etrurian art; and at the same time we must confess, with the latter, that the style of ornament, whether sculptured or painted, is essentially Greek. Between the years 1827 and 1830, more than four thousand vases were dug up in the neighbourhood of Vulci, in the very heart of the Etrurian territories,-descriptions of which were published by Millingen and the Prince of Canino. Many of them are covered with inscriptions in the Attic dialect: all that we have seen invariably preserve the Greek association of colours, that is to say, brown figures on a yellowish ground, black figures on a reddish ground, and red figures on a black ground. The last of these was a style of vase brought to the greatest perfection by Wedgewood; but we believe that the manufacture of such has been discontinued. All the subjects represented in the decorations, whether painted or in relief, are essentially Greek, and represent the divinities, costumes, and usages of Attica. Roman pottery is very closely connected with Roman history; for the Romans made |