CHINA-WARE. 



195 



upinJle, .m the upper end of which is fixed a small wince, 

 which is turned by a lad, while another forms his clay 

 articles. 



Modelling. This manipulation demands judgment and 

 taste, as well as delicacy of execution. The modeller forms 

 a correct model of the object, whether utensil or figure, 

 and, when this is dry, one or several blocks are formed 

 from it ; and these are used by the mould-makers, to cast 

 moods. With a thick layer of clay around the block, space 

 is left, into which is poured plaster of Paris, and left some 

 time for the water to evaporate, and the plaster to solidify 

 for the required manipulations, 



Pressing or squeezing the ware. The presser keeps all 

 his moulds on shelves ranged in a room around a heated 

 stove, which, by raising their temperature, promotes their 

 absorbence of the moisture in the clay in contact. For 

 convenience he has a number of moods for each kind of 

 vessel or utensil. He regards the size and strength of 

 each, and then cuts off a lump of clay sufficient for the 

 purpose ; and, after squeezing it in his hands, he beats it 

 to a suitable size and thickness. Usually ten or more of 

 these bats are prepared before proceeding to the next 

 operation. Taking the several parts of his mood, he 

 covers it with a proper portion of the bat, aud bosses it on 

 with a damp sponge, afterwards with his thumbs, forcing 

 it into all the parts, however angular they may be. With 

 a moistened sponge he carefully smooths the inner surface, 

 then trims off all extra portions from the edges, which he 

 moistens with slip (unevaporated body), places all parts of 

 the mood in proper contact, when needful, secures them 

 by a belt buckled round, and then ranges the whole on 

 the shelf around the stove, till sufficient moisture is ab. 

 sorbed to render the article capable of bearing, without 

 injury, other operations. In small moods are formed 

 ornamental figures, snips of jugs, spouts, handles, and 

 various utensils. When the series of moods is filled, the 

 presser empties them, again fills them, and while they are 

 drying, with proper tools be takes off all appearances of 

 seams, trims up the articles, and applies whatever appen- 

 dages are connected with his department. 



Handling the Ware. This is a distinct branch of the 

 day-man's manipulations, and regards fixing on vessels 

 the handles, spouts, snips, and ornamental figures proper 

 for them. Many of these are formed in moods, as by the 

 presser ; the handler having a number in his charge, 

 ranged around the stove for use. But for common vessels, 

 a box and screw is used to supply lengths of clay of a cer- 

 tain form, as required. An iron cylinder is secured to a 

 block fixed in the wall. Into this cylinder, at the bottom, 

 is placed a piece of lead, perforated agreeably to the in- 

 tended shape of the clay-length ; and for tubes, it has a 

 steel round pin firmly placed in the centre of the lead ; a 

 piston of iron is adapted to the cylinder at the end of a 

 powerful screw, which works through a bar above, by a 

 cross handle. Into this cylinder is put a lump of clay, and 

 the force of the screw on the piston causes the clay to pass 

 through the lead-piece, and it is received on a board, until 

 all is pressed through ; and these lengths are left a short 

 time to dry. The handler then cuts them in sizes, places 

 them in a proper curve, and prepares his vessels by trim, 

 tiling them. Having his handles, snips, and spouts before 

 him, with a sharp knife he cuts their edges level, also the 

 cylindrical side of the vessel, then cuts out the place for 

 the snip, or the aperture for the spout ; next moistens all 

 the edges with slip, fixes them properly, leaves them a 

 few minutes, examines and corrects any defects, and after 

 some time trims them, and lets them remain until ready 

 for being baked biscuit. 



Making of the Ware-biscuit. The potters' oven for bis. 

 cuit is usually larger than that for glaze ; and is, in form, 

 a cylinder ten or twelve feet high, and from ten to fifteen 



shale marl, carefully mixed with slate clay ; and the exer- 

 cise of judgment in this mixture is well compensated by 

 the demand for more serviceable bricks. In erecting the 

 oven, the builder lays the bricks, not in lime and sand 

 mortar, but in a mixture of fire clay and sharp sand with 

 water, or China clay and a weak solution of borax in 

 water ; making the joints so close and compact with this 

 lute, that the first baking of ware therein causes the whole 

 interior to become one compact shell of vitrefied fire clay, 

 precluding any admission of air into the interior, except 

 through the mouths; which, and also the bags or flues, are 

 carefully adapted in size, so as to prevent a continual cur. 

 rent of atmospheric air carrying off through the dome a 

 portion of the heat which ought to be appropriated by the 

 ware in the oven. The mouths on the outside are from 

 four to ten, according to the size, and communicate with 

 flues in the hearth of the oven, and bags of bricks, placed 

 edgewise, leaving an aperture of a few inches, fixed to the 

 inside of the cylinder; between each of which, in the 

 cylinder, is left a small bole, from which the fireman, by 

 means of a long iron rod, can draw his trials out of a sag- 

 ger placed opposite, or through which he can inspect the 

 gradual rising of the temperature of the oven, and its 



remaining at a certain heat during the time required for 

 earthenware, till the " heat will expel the moisture and 

 agglutinate," aa stated by Vauquelin, " the component*, 

 without effecting the fusion, which would render the ware 

 so homogeneous as to become brittle." But, for the best or 

 hard china ware, the temperature is raised till there is a 

 semi-vitresceuce of the components, calculated to be 80 to 

 100 Wedge wood, as the earthenware is 45 to 65 W., and 

 that for the glaze 10 or 7'5 lower. Felspar ware 115 W. 

 L>r W. Henry assigns others to different china wares: 

 Worcester, probably Flight and Barrs', 94, Chelsea 105, 

 and Derby 112 Wedgewood Here let it be understood, 

 that the Wedgtwood Pyrometer is no longer to be obtained, 

 and the real cause has not been assigned. This pyrometer 

 was invented by Thomas Massey, (a bailiff, in Mr Wedge- 

 wood's manufactory,) to determine the respective tempera- 

 tures of the biscuit and glaze ovens, and of the enameller's 

 muffles ; but he most resolutely declined communicating 

 to Mr Wedgewood the components of his dods, (or trial 

 prisms), and was prevented informing his brothers, Richard 

 and William the real secret died with him. Mr Wedge- 

 wood guessed at a clay for the purpose, and supplied philo- 

 sophers therewith, till its inaccuracy was exposed by Guy- 

 ton Morveau. Chemical reaction had completely affected 

 what useful properties for the purpose previously existed. 

 When the ware is so dry as to appear of an ash-grey colour, 

 the several articles are placed within each other carefully, 

 in saggers (probably from the Hebrew sagar, to burn, and 

 hence applied to a rolled leaf of tobacco used for being 

 burned, while the smoke is inhaled,); the shape is usually 

 that of a lady's band-box, though for plates round ones are 

 used, and some have triangular holes inside in three double 

 rows, for inserting stilts to keep the flat pieces separate. They 

 are formed of shale clay, (can marl,) sixty-seven ; slate clay, 

 (black marl,) thirty-three, well beaten together ; or ot 

 ground biscuit earthenware, sifted, and mixed with black 

 marl ; then formed into bats one inch thick, and placed 

 around a drum of -the shape and size required, mostly 

 twenty inches long, and oval in shape, and a bottom bat is 

 fastened by working the edges together. To prevent the 

 articles adhering from accidental excess of heat, pulverized 

 grit-stone is introduced between the ware and the sagger 

 bottom ; and the best china, jasper, pearl, &c., are imbedded 

 in ground flint, as a matrix, to prevent trauvi/ig (waving 

 or altering the shape and figure,) which might possibly en- 

 sue from high baking. The saggers are filled as full as 

 they will contain, and then are piled on eaoh other in ver- 

 tical bungs, each edge of a sagger being coated with a thick 

 wad of coarse brick clay or marl, and on which the next 

 upper sagger is imbedded ; and the whole pile resembles 

 one compact mass, secure from any deleterious effects 

 of the carburetted hydrogen, or sulphureous vapours 

 evolved by the fuel. In different parts of the oven are 

 pipe-saggers, to promote the regularity of the- baking ; and 

 opposite the aperture, between the bags, is a sagger with 

 its side perforated, and containing the trial pieces. When 

 the oven is filled, and all arranged, the door-way is built up 

 with bricks, and plastered over with mud, and short iron 

 bars are hooked into an iron frame that goes along the 

 edge of the doorway, and is connected with two or three 

 ranges of very strong booking-pieces of iron, that go round, 

 like hoops, one at the commencement of the dome, and two 

 others on the cylinder, and which guards are necessary to 

 prevent the high temperature of the whole causing the cy- 

 linder to crack or bilge out After the first eight hours, the 

 baking continues of a regular heat for about thirty-five hours 

 more, and then is rapidly urged on for three hours longer. 

 An experienced fireman will judge with tolerable accuracy of 

 the process of baking, by the appearance of the saggers, and 

 by inspection of trial pieces made of brick clay, in the shape 

 of rings and small gallipots, taken from different parts of 

 the oven, and which present a varied tint at different de- 

 grees of temperature, compared with a trial known to have 

 been properly baked, and kept as a standard for determin- 

 ing the process. When the fireman knows the nature of 

 the coals he uses, he will frequently save to his employer, 

 (in addition to the production of superior ware,) the con- 

 sumption of coals exceeding the amount of his wages. When 

 the baking is completed, the mouths are drawn (the fuel is 

 extracted) as quickly as possible ; the whole is left to cool 

 for several hours, (the entrance is opened,) the clammings 

 are taken down, the saggers are emptied as quickly as pos- 

 sible into baskets, and carried into the sorting room, where 

 they are carefully examined, and by sound tried whether 

 fit for further processes, and when so, placed in the biscuit 

 warehouse ; as good, when perfect ; as seconds, when 

 lightly injured, yet sound; and, as lump, or thirds, when 

 defective, yet sound in structure. All cracked articles are 

 cast aside on the shord-rack (heap of pot-sherds). The ex- 

 pansion and contraction of the mass expediting the de. 

 struction of the oven, manufacturers strive to keep their clay 

 stock up, so as constantly to supply ware, without allowing 

 the oven to be lower than is absolutely proper for the men 

 to bear while drawing, and again setting-in. The earthen, 

 ware, in its biscuit state, has a dry and gritty roughness ; 

 the china, a resemblance to statuary marble, devoid of any 

 lustre on its surface ; but, when of a good body, and excel 

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