278 



ENCAUSTIC TILES 



834 



LEATHER. Loathcr glazed upon ono surface, tho so-callod 

 enamelling composition being in all respects analogous to the ordinary varnishes. 

 Instead of enamelling tho grain surface, as is usually done, Mr. Nossiter removes that 

 surface by splitting or buffing, and then produces what is called ' a finish ' upon the 

 surface thus formed, by means of a roller, or glass instrument. Tho flesh side of tho 

 skin maybe thus prepared for enamelling; and it is less liaMr to crack, and tho 

 enamel to become cloudy on it than on tho grain side. See LEATHKII. 



ENARCITE. An arsonio-sulphido of copper, occurring in the form of a grey or 

 iron-black mineral with metallic lustre. It is found in certain mines iu Mexico, Peru, 

 and Chili. 



ENCAUSTIC PAINTING. A mode of painting with heated or burnt wax, 

 which was practised by the ancients. Tho wax, when melted, was mixed with as 

 much colour, finely powdered, as it could imbibe, and then the mass was spread on 

 the wall with a hot spatula. When it became cold, the designer cut tho lines with a 

 cold pointed tool, and other colours were applied and melted into tho former. Many 

 modifications of the process have been employed. Amongst tho moderns, tho term 

 has been improperly given to some cements, which have nothing of an encaustic 

 character about them. 



ENCAUSTIC TIIiES are tiles in which any design has been produced by fusing 

 in other colours than such as form the colour of the ground. Encaustic tiles are of 

 all ages, and we find them representing every variety of subject. 



The manufacture of encaustic tiles has been carried to great perfection in our own 

 times. It will be well to consider this manufacture in connection with Tessera, there 

 being, indeed, no difference in the first production of tiles or tesserae, except that tho 

 latter are at first moulded with the spaces which are to be filled in with the coloured 

 clays to form tho patterns impressed upon them. 



The Koman tesserae, of which many very fine examples have been discovered in this 

 country, were often formed of natural stones (sometimes coloured artificially), but 

 generally of baked clay. Tho beauty of many of these has 

 led to the production of modern imitations, which have 

 been gradually improved, until, in the final result, they far 

 exceed any work of the Komans. 



About half a century since, Mr. C. Wyatt obtained a 

 patent for a mode of imitating tesselated pavements, by in- 

 laying stone with coloured cements. Terra-cotta, inlaid with 

 coloured cements, has also been employed, but with no very 

 marked success. 



Mr. Blashfield produced imitations of those pavements, 

 by colouring cements with the metallic oxides : these stood 

 exceedingly well when under cover, but they did not endure 

 the winter frosts, &c. Bitumen, coloured with metallic 

 oxides, was also employed by Mr. Blashfield. In 1839 Mr. 

 Singer, of Vauxhall, introduced a mode of forming tesserae 

 from thin layers of clay. Those were cut into the required 

 forms, dried and baked. In 1 840 Mr. Prosser, of Birmingham, 

 discovered that if the material of porcelain (china clay) be reduced to a dry powder, 

 and in that state be compressed between steel dies, tho powder is condensed into 

 about a fourth of its bulk, and is converted into a compact solid substance of extra- 

 ordinary hardness and density. 



This process was first applied to the manufacture of buttons, but was eventually 

 taken up by Mr. Minton, and, in conjunction with Mr. Blashfield, Messrs. Wyatt, 

 Parker, and Co., it was carried to a high degree of perfection for making tesserae. 

 The new process, invented by Mr. Prosser, avoided tho difficulty altogether of using 



This change in tho order of tho potter's operations, although very simple in idea 

 (and a sufficiently obvious result of reflection on tho difficulties attending tho usual 

 course of procedure), has nevertheless required a long series of careful experiments 

 to find out the means of rendering it available in practice. 



The power which the hand of the potter has exercised over his clay has boon pro- 

 verbial from time immemorial, but it is limited to clay in its moist or plastic state ; 

 and clay in its powdered state is an untractablo material, requiring very exact and 

 powerful machinery to bo substituted for tho hand of tho potter; in order, by great 

 pressure, to obtain the requisite cohesion of tho particles of clay. 



In the new process, tho clay, or earthy material, after being prepared in the usual 

 manner, and brought to the plastic state, as above described (except that no kneading 

 or tempering is requisite), is formed into lumps, which are dried until the water is 

 evaporated from the clay. 



