RERAMIC STUDIO 
195 
ferriA>re: 
lociaiMi.O.of 
3 P 
Four a. /a JootcUle. . 
Four, kiln. Houille, coal. Regard, spyhole. Ferrures, iron brace.'!. Largeur, width. Epaisseur, thickness. 
K.-portt du four 
ULfie iixwAni-XX. 
f,<^.34 
Coupe, section. Porte, door. Fcute, vault. Globe, baking chamber. 
The firing chamber F ends in a spherical vault pierced by 
square openings (Fig. 31 and 33), and a central chimney, 
through which the lower chamber, where the firing of porcelain 
is done, communicates with the upper chamber G, where the 
baking is done. This upper chamber is surmounted by a cone 
ending in a rectangular or cylindrical flue H placed in the axis 
of the draft, to allow the escape of the products of combus- 
tion; it is the chimney. 
At the bottom of the firing chamber are symmetricallj- 
placed the three fire mouths A,A',A" (Fig. 34). In R (Fig. 31 
and 35) are the openings through which the flame enters the 
kiln. The relation between the surface of these openings and 
that of the openings O and C for the entrance into the baking 
chamber, is 3 to I according to the rule. 
The progress of the firing is watched through onh- one 
spyhole in the door of the firing chamber, made about at two- 
thirds of the height of the door. This spyhole is roughh^ made 
bj^ four rectangular tiles (Fig. 36 and 37). It is closed with a 
stopper (Fig. 38) in fire brick, in the axis of which a hole has 
l^^^^^l 
mmd 
F.e 3G 
4'J-7 
