2M) POTTERY* 



li^nofr of the same density, and consisting of flints 

 calcined, ground, and suspended in water. The 

 mixture is then dried in a kiln ; and being after- 

 wards beaten to a proper temper, it becomes fit for 

 being formed at the wheel into dishes, plates, 

 bowls, &c. When this ware is to be put into the 

 furnace to be baked, the several pieces of it are 

 placed in cases made of clay, called seggars, which 

 are piled one upon another in the dome of the 

 furnace ; a fire is then lighted, and the ware is 

 brought to a proper temper for glazing, and in this 

 state it is called biscuit. Before the glazing takes 

 place it is coloured or painted, Formerly the 

 painting was done by the pencil by hand. It is 

 now commonly effected by taken impressions on 

 pdper from engraved copper plates, and transfer- 

 ring them to the earthenware while the ink is wet. 

 The ink is instantly absorbed by the biscuit, and 

 the paper is washed oif. The ink for the blue and 

 white ware is made from oxide of cobalt. It is 

 then dipped into a glaze, made by mixing together 

 in water, till it becomes as thick as cream, one 

 hundred and twelve parts of white-lead, twenty- 

 four parts of ground flint, and six parts of ground 

 flint-glass. The ware, by being bakedj acquires a 

 strong property of imbibing moisture, and when 

 dipped into the glaze, therefore, it greedily attracts 

 it into its pores, and presently becomes dry. It is 

 then exposed a second time to the fire, by which 

 means the glaze it has imbibed is melted, and a 

 thin glassy coat is formed upon its surface. The 

 colour of the coat is more or less yellow, according 

 as a greater or less proportion of lead has been 

 used. The lead is principally instrumental in pro- 

 ducing the glaze, as well as in giving it the yellow 

 colour} for lead, of all the substances hitherto 



