MOSAIC WOOL-WORK 367 



threads of glass. These .rods and threads are kept in bundles, and arranged in sets 

 corresponding to their colours, each division of a set presenting every desired shado. 

 A piece of dark slate or marble is prepared, by being hollowed out like a box, and 

 this is filled with plaster-of-Paris. Upon this plaster the pattern is drawn by 

 the artist, and the mosaicisti proceeds with his work by removing small squares of tho 

 plaster, and filling in these with pieces cut from the rods of glass. Gradually, in this 

 manner, all the plaster is removed, and a picture is formed by the ends of the fila- 

 ments of coloured glass ; these are carefully cemented together by a kind of mastic, 

 and polished. In this way is formed, not only those exquisitely delicate mosaics 

 which were, at one time, very fashionable for ladies' brooches, but tolerably large 

 and often highly-artistic pictures. Many of our readers will remember the mosaic 

 landscapes which rendered tho Italian Court of the Great Exhibition so attractive ; 

 and in the Museum of Practical Geology will bo found a portrait of the late Emperor 

 of Russia, which is a remarkably good illustration of mosaic-work on a large scale. 

 We may remark, in passing, that the whole process of glass-mosaic is well illustrated 

 in this collection. 



Tho next description of mosaic-work requiring a word is the manufacture of 

 Tunbridge. The wood-mosaics of Tunbridge are formed of rods of wood, varying in 

 colour, laid one upon the other, and cemented together, so that the pattern, as with the 

 glass-mosaics, is produced by the ends of the rods. 



X&OSAXC GOX.35. For the composition of this peculiar alloy of copper and zinc, 

 called also Or-molu, Messrs. Parker and Hamilton obtained a patent in November 

 1825. Equal quantities of copper and zinc are to be ' melted at tho lowest tempera- 

 ture that copper will fuse,' which, being stirred together so as to produce a perfect 

 admixture of the metals, a further quantity of zinc is added in small portions, until 

 the alloy in the melting-pot becomes of the colour required. If the temperature of the 

 copper be too high, a portion of the zinc will fly off in vapour, and the result will be 

 merely spelter or hard Bolder ; but if the operations be carried on at as low a heat 

 as possible, the alloy will assume first a brassy-yellow colour ; then, by the introduc- 

 tion of small portions of zinc, it will take a purple or violet hue, and will ultimately 

 become perfectly white, which is the appearance of the proper compound in its fused 

 state. This alloy may be poured into ingots ; but as it is difficult to preserve its 

 character when re-melted, it should be cast directly into the figured moulds. The 

 patentees claim exclusive right of compounding a metal consisting of from 52 to 55 

 parts of zinc, out of 100. 



Mosaic gold, tho aurum musivum of the old chemists, is a eulphuret of tin. See 

 AXLOYS. 



MOSAIC WOOIi-WORK. There is no branch of manufacture which is of 

 n, more curious character than the mosaic wool-work of the Messrs. Crossleys of 

 Halifax. 



By referring to the article MOSAIC there will be no difficulty in understanding how 

 a block of wood, which has been constructed of hundreds of lengths of coloured 

 specimens, will, if cut transversely, produce a great number of repetitions of the 

 original design. Suppose, when we look at the transverse section presented by tho 

 end of a Tunbridge block, we see a very accurately-formed geometric pattern ; this 

 is rendered perfectly smooth, and a slab of wood is glued to it. When the adhesion 

 is secure, as in a piece of veneering for ordinary cabinet-work, a very thin slice is 

 cut off by means of a circular saw, and then we have the pattern presented to us in a 

 state whicli admits of its being fashioned into any article which may be desired by 

 the cabinet-maker. In this way, from one block, a very large number of slices can 

 be cut off, every one of them presenting exactly the same design. If lengths of 

 worsted are substituted for those of glass or of wood, it will be evident that the result 

 will be in many respects similar. By a process of this kind the mosaic rugs with 

 very remarkable copies from the works of some of our best artists are produced. In 

 connection with this manufacture, a few words on the origin of this kind of work will 

 not be out of place. 



The tapestries of France have been long celebrated for the artistic excellence of 

 the designs, and for the brilliancy and permanence of the colours. These origi- 

 nated in Franco, about the time of Henry IV., and tho manufacture was much 

 patronised by that monarch and his minister Sully. Louis XIV. and Colbert, how- 

 ever, were the great patrons of the beautiful productions of tho loom. Th'e minister 

 of Louis bought from the brothers Gobelins their manufactory, and transformed it 

 into a royal establishment, under tho title of Le Teinturicr Parfait. A work was 

 published in 1746 in which it was seriously told that tho dyes of the Gobelins 

 had acquired such superiority that their contemporaries attributed the talent of these 

 celebrated artists to a paction which one or the other of them had made with the 

 devil. 



