Origin of Glass. plate-glass for mirrors, &c., was made at Lambeth in 1673, by Venetian workmen, brought over by the Duke of Buckingham. The date of the introduction of the art of glass-making THE precise period when the art of glass-into Scotland took place in the reign of James making was first discovered is unknown; but VI., in the year 1610. it is certain that the knowledge of the art is of At what period the art of simply staining, the highest antiquity, having long preceded tinging, or colouring glass was first discovered, the Christian æra. This fact is established by is uncertain, but tradition says it was first dismany circumstances, and among others, by covered by an Egyptian king; it is, however, that of glass beads and other ornaments having certain that the art was known in Egypt sevebeen found adorning the bodies of Egyptian ral thousand years since, the most beautiful mummies, which are known to have been up-imitations in glass of precious stones of all wards of three thousand years old. Glass is colours manufactured there, and of this antialso mentioned by the Greek poet Aristo-quity, being still extant. phanes, four hundred years before the birth of Christ. The first painted glass done in England was in the time of King John. Previous to this period, all glass of this kind was imported from Italy; but as early as the reign of Henry III., England boasted of several eminent artists in glass-painting. System of the Ancient The first manufactories of glass of which we have any account, were erected in Tyre, an ancient Phoenician city on the coast of Syria. The art afterwards extended to the towns of Sidon and Alexandria, which places also became famous for their glass-ware. From Syria the art of glass-making found its way to Geometric Greece, and from thence to Rome, where a company of glass manufacturers established themselves in the reign of Tiberius. The seat of the art of glass-making in process of time PERHAPS the following quotation from Spenchanged from Rome to Venice, or rather to Murcano, a small village in the vicinity of that city. For many years the Venetian glass, in its various forms, supplied nearly the whole of Europe for that description of ware. From Venice the art of glass-making found its way to France, where an attempt was made to rival the Venetians in the manufacture of mirrors in the year 1634; but subsequent attempts and improvements at length enabled the French speculators not only to rival, but to excel the Venetians; and about the end of the seventeenth century, they succeeded in casting plates of glass for mirrors, of a size which had been thought unattainable. ser's "Faerie Queene (if it has never been "The frame thereof seem'd partly circulare To OBTAIN HEIGHTS WHICH CANNOT BE At what period the manufacture of glass was first introduced into England is uncertain, but there is reason to believe that glass was made so early as the beginning of the fifteenth century. This appears from a contract, dated 1439, between John Prudde, of Westminster, MEASURED.-Take any two rods of unequal glazier, and the Countess of Warwick, to emlength, place the short rod at any convenient bellish a magnificent tomb for her husband, in distance from the building, and the long rod which Prudde is bound to use "no glass of at such a distance from it, that looking over England, but glass from beyond the seas." the short rod to the top of the building, the top of the long rod shall cut that sight. Then say, as the distance between the rods is to the height of the long rod over the short one, so is the distance of the long rod from the building add the short rod, and you have the height of to the height of the building, to which result the building. Glass windows, according to Bede, were first introduced into England in the year 647, to glaze the church and monastery of Weremouth. Another authority attributes the introduction of this luxury to Bishop Winifred, who died in 711; it seems, therefore, probable, that glass windows were first introduced into England about the end of the seventh or FIREPROOF AND WATERPROOF CEMENT.-To beginning of the eighth centuries. Previous half-a-pint of milk put an equal quantity of to this, and for many centuries afterwards, the vinegar, in order to curdle it; take the curd use of window-glass was confined entirely to from the whey, and mix it with the whites of buildings appropriated to religious purposes, four or five eggs; beat them well together; until the close of the twelfth century, when add a little quicklime through a sieve, till it glass windows became common in England. has acquired the thickness of paste. In 1557, the finer sort of window-glass was this cement, broken vessels of all kinds may manufactured at Crutched-Friars, in London. be mended; it dries quickly, and resists the The first flint-glass was manufactured at action of water, as well as a considerable Savoy House, in the Strand, and the first degree of heat. With On Architectural and Enterior Ornament. measure we find more originality displayed in the sculptures of other objects more in consonance with the character of the edifices they were intended to adorn. Before the Romans were sufficiently advanced in artistic knowledge, they used the chefs d'oeuvre belonging to Grecian towns fallen EDUCED to its own into their power. With regard to interior scientific proportions, ornaments, they had a method of detaching and depending merely from the walls large portions of the paintupon them to please ings and sculptures entire, which they afterthe eye, architecture wards affixed to the sides of the interiors of would occupy a far their own habitations, surrounding them with a border of stucco. Winckelmann, in his less prominent posi-Essay on the Works of Art discovered at tion than it at present does; but when Herculaneum," states that he found several judiciously decorated paintings detached from the walls, which they by the application of merely rested against, the owners of the manornament, its beau- sions having probably intended to fix them, ties become the more had not their purpose and their life together developed while acci- been arrested by the inexorable hand of dental falsity of condestiny. struction is in a great concealed. Thus depending necessarily upon decoration, it is essentially requisite that close attention should be paid to that art, not only by the decorator, but also the architect himself, for in the disposition of exterior ornament it becomes bis especial province. It has been justly observed that, "in order to preserve harmony and consistency throughout the several relative parts of an edifice, one sole eye and mind should superintend and control the whole of the artists and workmen employed"-and this must be that of the architect. From the want of this being carried into practice, how many abortions have there not been produced which otherwise might have reflected credit upon their constructors? In many of the finest of the Italian structures, unity is observable throughout, and who shall say that this end could have been effected without the utmost attention had been paid to the proper disposition of parts in order to produce a harmonious whole? In the earlier periods of Grecian architecture, interior decoration was not employed, being esteemed as an useless luxury; but in later times, when the growth of civilisation increased wants and created luxuries, the adornment of the interiors of edifices became common, and from that time until the present the taste has continued. Most of the early ornamental designs for architecture were copies from nature, such as leaves, flowers, fruit, and so on; but presently The columns and their accessories probably owe their origin, among the Greeks, to the imitation of those parts which, in the most ancient temples (built of wood), were indispensable for the purpose of sustaining the edifice generally, and more particularly the ceiling. When, subsequently, they came to use stone instead of wood, these parts were executed with a greater degree of care,-they were invested with beautiful shapes and proportions, and agreeably diversified in outline by the variety of their members. In order to avoid the monotony which this quantity of produce, they proceeded to embellish the difsurface naked and uniform would after all ferent members or divisions with certain ornaments, for illustrations of which we must refer our readers to the "Glossary." department of art which requires greater care In conclusion, we may add that there is no and skill, and a more refined taste, than that which superintends the distribution of ornament; and, therefore, the artist, as a general rule, should adopt this maxim-to be sparing rather than profuse, for it would seem but as paying little respect to architectural skill to hide its produce with the very excess of adornment. STATISTICS OF RAILWAY EMPLOYMENT. From a return of the number and description of persons employed on the railways of the United Kingdom (open for traffic), on the 1st of May last, it appears there were employed on seventy-four railways, comprising an extent of 3,305 miles, 47,218 persons. From a similar return on lines and branches in course of construction at the same period, amounting to 128, and comprising an extent of 6,455 miles, it appears there were 256,509 persons employed. Total, 303,727. Rules for Ornamental Drawing.Ornamental Leading of Windows. FIG. 9 is a diagramic outline of the elevation ANTERIOR to the introduction of sashed winof a rose in the abaci of the capitals of the pilasters of the frontispiece of Nero at Rome, which shows the manner of striking the out line. Fig. 9. Fig. 10 is a complete outline of same. dows, those formed of lead, disposed according to ornamental devices, were employed, and formed an important branch of the glazier's profession. In order fully to appreciate the appearance of these windows, it is only necessary to view some of the old English mansions, built during the reigns of the Virgin Queen and her successor, when the observer will be at once struck with their extreme beauty and magnificence. For a considerable period, however, this description of windows have had little attention bestowed upon them, other than that of curiosity; but at the present time they have suddenly advanced into popularity along with the resuscitation of ancient English architecture, in connection with which they become indispensable. Such being the case, it is essentially necessary that ornamental leading should be well studied by those desiring to excel in the art, and they cannot do better than visit the many beautiful specimens which lie scattered! about the metropolis and the provinces. Fig. 10. STAINS FOR WOOD.-Mahogany Colour: Take one pound of logwood, boil it in four quarts of water; add a double handful of walnut-peeling; boil it up again; take out the chips, and add a pint of the best vinegar, and it will be fit for use.-Another: Take some linseed oil, and mix with it a little brown umber in powder, and oil of wood; a little red lead may be added.-Another: Take two ounces of gum tragacanth, break it in pieces, and put it into a quart of rectified spirits of wine; let the bottle stand in a warm place; shake it frequently, and, when dissolved, it is fit for use.-For Wood or Bone: Take powder of Brazil, and mingle it well with milk, but so that it be very red, and put therein either wood or bone, letting it lie eight or ten days, when it is fit for use. Fig. 1. Fig. 2. The above engravings represent an ornamental design for a window (Fig. 1), and a lancet-shaped light (Fig. 2). At first sight the former may seem rather complicated, but if the pattern be previously formed on paper, to the size required, the glass can be very easily cut into the various forms. By the introduction of stained glass this light has a most beautiful effect (with "diapered" rays) in the long skittle-shaped pieces, and in the rosette in the centre. This light would be a very economical one for the chancel of a church, and it is really surprising that ornamental glazing is so scantily introduced into the new erections daily being made over the kingdom. First Steps to Geometry. (Continued from page 119.) PROBLEM XXVII. To describe a regular dodecagon on a given A Bisect A B in c. Draw CD perpendicular to PROBLEM XXVIII. Fig. 2 is a lancet-shaped light of a very line. simple pattern, and quite as easily cut as the lozenge-shaped quarries now in use; and has a much better appearance in a large window if the diamond-shaped pieces were in stained and the remainder were in ground or 'diapered" glass. It would form a very neat and ornamental light for a staircase, that could be executed, and at a moderate price, by any glazier. An excellent effect is produced in windows of this kind, by what is termed diapering," where designs of flowers, foliage, &c. are executed in ground glass, upon the transparent or stained ground. The method, which is as follows, is very simple:-Take a large camel-hair brush, dip the end of it in a small quantity of amber oil, so that the brush may not take up so much of the oil as to make A B. From A or B as a centre, and with the it run on the glass; holding the brush upright length A B, cross CD in E; and from E, with in the hand, go over every part that you wish E A as radius, describe the arc A D; then the to appear as ground glass, not painting in point D will be the centre of the polygon strokes, but dabbing everywhere till the glass required. is evenly covered with the oil, taking care there is no part where the oil looks fluid. Then take a mixture of one part of white oxide of tin, and three parts of common flux, well ground and mixed together; placing a portion of this in a lawn sieve, sift it carefully Divide 360 by the number of sides of the and evenly over the surface of the glass. It given polygon, and the quotient will be the must now be left at least six hours to dry, and angle at the centre; and this angle being subthe superfluous powder brushed off very tracted from 180, the difference will be the lightly with a badger-hair softener. The angle at the circumference required. Accorddesign may be finished and improved by ing to this method, the following table has sharpening the lines, introducing other been calculated, showing the angles at the touches, &c., by scraping away the colour centres and circumferences of regular polywith a blunt piece of wood cut to the width gons, from three to twelve sides inclusive. of the line required, taking care not to touch the glass with the fingers. If now submitted to the heat of a furnace, the white colour will be found fluxed to the glass so strongly that no common means will remove it. Another mode is to draw the design on ground glass, using a strong spirit varnish, which will, where it touches, restore its transparency; this method is certainly not so durable as the former, but yet it will last many years; it is even doubtful whether regrinding would entirely remove it. ference of a given polygon. Names. Sides. Trigon Angles at the Centre. deg. min. Angles at the Circumference. deg. min. 3 120 0 60 0 90 0 6 0 60 0 7 51 25 5-7 128 342-7 Heptagon PROBLEM XXIX. To make a triangle similar and equal to a STRENGTH OF MATERIALS.-Coulumb found that the force of torsion is equally powerful in wires annealed and unannealed, they performed their vibrations in equal times. A tempered bar required also as much force to given triangle. deflect it to a given angle as a hard one of the same dimensions. A soft bar, a spring tempered, and a hard one, were bended to equal angles by five pounds; with six the hard bar broke, with seven the soft one bended, but returned as far from its new position, upon the removal of the weight, as if it had not bended; the elastic bar was broken by eighteen pounds. 10. A Varnish for Wood or Metal, representing a Golden Colour. Take two ounces of gum-sandarach, one ounce of litharge of gold, and four ounces of earthern vessel till they appear of a transclarified linseed oil; boil them in a glazed parent yellow colour. 11. Mastic Varnish. DISSOLVE in a glazed earthern vessel a small quantity of colophonium, or boiled turpentine, until it becomes black and friable, and gradually throw into the mixture three times as much amber finely pulverised, adding, from time to time, a little spirit or oil of turpentine. When the amber is dissolved, besprinkle the Dissolve mastic in spirits of turpentine by mixture with the same quantity of sarcocolla means of a sand-bath; then strain it through a gum, continually stirring the whole, and add fine sieve, and afterwards place it for a fortspirits of wine until the composition becomes night or three weeks in a well-corked bottle, fluid; then strain it through a piece of hair- in such a manner as to allow the light of the cloth, pressing it between two boards. This sun to act freely upon it, which will cause a varnish, when mixed with ivory black, should large precipitation of mucilaginous matter, be applied in a warm place. and render the varnish quite clear and transparent. 4. Colourless Varnish. 12. Varnish for Drawings, &c. Dissolve eight ounces of gum sandarach and two ounces of Venice turpentine in thirty-two Take some clean parchment cuttings, and ounces of alcohol by a gentle heat. To make boil with water in a glazed pipkin until they a harder varnish of a reddish cast, dissolve produce a very clear size; then keep for use. five ounces of shell-lac and one of turpentine in thirty-two ounces of alcohol, by a very | 13. Varnish for Musical Instruments, Plumtree, gentle heat. 5. Solution of Copal. Triturate an ounce of powder of gum copal, which has been well dried by a gentle heat, with a drachm of camphor, and, while these are mixing together, add, by degrees, four ounces of the strongest alcohol, without any digestion. 6. Gold-Coloured Varnish. Pound separately four ounces of stick-lac, four ounces of gamboge, four ounces of dragon's blood, four ounces of anotta, and one ounce of saffron; put each of them separately into a quart of alcohol, and expose them for five days in a narrow-mouthed bottle to the sun, or keep them during that time in a very warm room, shaking them every now and then in order to hasten the solution. When they are all melted mix them together. Mahogany, or Rosewood Furniture, &c. Put together, into a tin can, one gallon of rectified spirits of wine, twelve ounces of mastic, and a pint of turpentine varnish, and keep them in a very warm place, shaking them now and then until they are perfectly dissolved; then strain, and the mixture is fit for use. It may, if necessary, be diluted with turpentine varnish. 14. Camphorated Copal Varnish. Take of powdered copal, four ounces; essential oil of lavender, twelve ounces; camphor, a quarter of an ounce; and as much spirit of turpentine as will produce the required consistency. Heat the oil and the camphor in a small matrass, stirring them, and putting in the copal and turpentine in the same manner as for gold-coloured copal varnish (see page 115 ante). 7. Caoutchouc or Gum-Elastic Varnish. 15. Ether Varnish. Take eight ounces of gum-elastic, pound it Take one ounce of amber-coloured copal well, and put it upon the fire in a vessel con- finely powdered, and place it in a flask con |