814 NEW YORK STATE MUSEUM 



and the body and the former absorbs elements of the latter, alter- 

 ing its composition and consequently its properties. This over burn- 

 ing of the glaze is the principle nsed by the Chinese to produce 

 their celebrated crackle ware. 



Kilns. The type of kiln used depends on the ware, the tem- 

 perature to be obtained, and the fuel. 



In this country a round vertical kiln is generally used for both 

 the first and the second burning. The first burning, which is known 

 as the biscuit burn, is done at a lower temperature. The second 

 firing is done in a similar kiln, known as the Glost kiln. After the 

 ware has been burned with a glaze on it, it is sometimes decorated 

 and then fired a third time in what is known as a muffle kiln. 



The two points necessary in a kiln are first equal distribution of 

 heat, and secondly economy of fuel, with a development of the 

 maximum heat. 



Most of the kilns used are down-draft, and in these we get a 

 more complete combustion, for the reason that the air and gases 

 must follow a longer path, and consequently, get a better chance to 

 mix. The continuous type of kiln is little used in this country, 

 though it has been used with marked success abroad for the burn- 

 ing of both white earthenware and porcelain. 



Methods of decoration 



These seem to deserve special mention, as in many cases they 

 form an important and distinct branch of the pottery industry. 



Decoration may be imparted to- a ware in three ways: 1) by the 

 production of a raised design; 2) by covering the ware with a solid 

 color; 3) by the decoration of the surface with various designs, ap- 

 plied to the ware in one way or another. Common red earthen- 

 ware seldom receives any decoration, though this has been decorated 

 more within the last year or two. Stoneware, yellow ware and 

 Kockingham ware often have the surface ornamented with a raised 

 design, which is imparted to the article in molding it. Stoneware 

 is often decorated under the glaze with crude designs made by 



