TEXTILE FABRICS 979 



buildings erected in Italy between tho 12th and 17th centuries. The clay sketches 

 and models of Michael Angelo, and other great sculptors, were rendered in terra 

 cottas. Bramante employed terra cotta in decoration. 



The merit of reviving in England the manufacture of terra cotta belongs to 

 Josiah Wedgwood, who in 1770 established large -works in Staffordshire. About 

 1790 a, pottery was established at Lambeth for the manufacture of decorative works ; 

 and terra cotta was made for many years by a lady of the name of Coade, and after- 

 wards by Coade and Sealey. The chief materials used by them were the Dorset and 

 Devonshire clays, with fine sand, flint, and potsherds. The chief portion of the old 

 coats-of-arms above the shop-fronts of London were made of this terra cotta. About 

 fifty years ago, Mr. Bubb, the sculptor, had a manufactory for terra cotta. Tho frieze 

 of the Opera in the Haymarket is an example of his work. 



To explain the mode of executing any work in terra cotta, it is best to describe the 

 proper meaning of the words ' modelling,' ' moulding,' and ' casting.' 



A model is an original work made by the sculptor in clay, and worked out by the 

 fingers and small tools made of bone and steel, varying from about 6 to 10 inches in 

 length. This original work of the artist is allowed to dry, and then the moulding 

 operation commences. This process is effected by mixing plaster-of-Paris with 

 water to the consistency of thick cream ; this is spread over the model, and when 

 it has set it is removed in sections, which, when again carefully united, form the 

 mould, in which either clay or metal can be cast, and receive the form of the original 

 work. For terra-cotta work, unless many copies of the original are wanted, moulds 

 are not employed. When only one or two copies of a work are required, the original 

 models are built up in a cellular manner, they are then dried and removed to a kiln 

 and baked, being a perfectly original work. 



When moulding is performed for terra-cotta works, sheets of clay are beaten on a 

 bench to the consistency of glazier's putty, and pressed by the hand into the mould; 

 according to the magnitude of the work and the weight it may have to sustain, tho 

 thickness of the clay is determined and arranged, and here consists a part of the art 

 it would be impossible to describe, and which requires years of experience in such 

 works to produce great works and fire them with certainty of success. 



At the Crystal Palace, Sydenham, are several large works manufactured by Mr. J. 

 M. Blashfield, who has extensive terra-cotta works at Stamford. The figure of 

 ' Australia,' modelled by John Bell, nine feet in height, and burnt in one piece ; the 

 colossal Tritons modelled by the same artist, and other works, are examples. After 

 the moulded article has become sufficiently dry, it is conveyed to a kiln. A slow fire 

 is first made, and quickened until the heat is sufficient to blend and partially vitrify 

 tho material of which the mass is composed ; when sufficiently baked, the kiln is 

 allowed to cool, and the terra cotta is withdrawn. 



A very fine red terra cotta, resembling that imported from Copenhagen and 

 Belgium, has within the last few years been manufactured at Watcombe, near 

 Torquay, in Devonshire. 



TERRA. DI SIENNA is a brown ferruginous ochre, employed in painting, 

 obtained from Italy. It is a hydrous sesquioxide of iron, containing traces of 

 arsenic ; from which we may infer it is derived mainly from decomposition of 

 arsenical pyrites. It is calcined before being used as a pigment, and is then known 

 as burnt sienna. Raw sienna is not much employed; it contains water, which the 

 calcined does not. 



TERRA JAPONTCA. See ACACIA ; CATECHU; GAMBIER. 



TESSERJE. See TILES and ENCAUSTIC TILES. 



TESTS are chemical reagents of any kind, which indicate, by special characters, 

 the composition of the body to which they are applied. Analytical chemistry is based 

 on the application of tests. See Watts's ' Dictionary of Chemistry.' 



TETRADYMXTE, or Telluric Bismuth. A telluride of bismuth, frequently con- 

 taining sulphur. It is a common associate of gold. 



TEXTILE FABRICS. The first business of the weaver is to adapt those parts 

 of his loom which move the warp to the formation of the various kinds of ornamental 

 figures which the cloth is intended to exhibit. This subject is called tho draught, 

 drawing or reading in, and the cording of looms. In every species of weaving, 

 whether direct or cross, the whole difference of pattern or effect is produced, either 

 by the succession in which the threads of warp are introduced into the heddles, or by 

 the succession in which those heddles are moved in the working. Tho heddles being 

 stretched between two shafts of wood, all the heddles connected by the same shafts, 

 are called a leaf ; and as the operation of introducing the warp into any number of 

 leaves is called drawing a warp, the plan of succession is called the ' draught.' When 

 this operation has been performed correctly, the next part of tho weaver's business is 

 to connect the different leaves with the levers or treddles by which thev are to be 



3B2 



