228 
RERAMIC STUDIO 
GRAND FEU CERAMICS 
Vin.— Kilns (Continued) 
Taxile Doat 
AS I had constructed my coal kiln in order to become familiar 
with the handling of a firing and to detennine the adoption 
of my ceramic bodies, half of it was filled with white vases, either 
cast, pressed or turned, without decoration, but modeled with 
different pastes; the other half contained bas reliefs Wedgwood 
style and biscuit figures Sevres style, the sale of which not onlj- 
covered all the expense of firing but left me profits which I in- 
vested in new trials. As the kiln had up draft, the white 
pieces were placed in the lower part, so as to get the benefit of 
the highest heat, and the biscuits, which required a lighter fire, 
to avoid the glassy appearance, were placed in the upper pai't 
of the firing chamber, and ever^^ time pieces for the following 
firing were baked in the baking chamber. 
After I had logically and scientifically determined the 
porcelain and grfes bodies which were best suited to my work, 
I stopped the period of trials, I destroyed my first kiln and 
built my second one, in my residence, at Sevres. Experience 
having taught me that the up draft has the great disadvantage 
of compromising seriously the results bj" brutalh" striking with the 
mo.st intense heat the bottom of the piles of saggars, thus mak- 
ing them liable to occasionally sag and to disastrouslj^ shake 
the other piles, also that the heat being unevenly distributed, 
there is between the upper and the lower parts of the kiln a 
difference of temperature which is sometimes more than 50° C, 
I adopted the down draft. 
f'g ^7 
This second kiln, wliich I use now (Figs. 47, 48, 49, 50), is 
of the cylindrical vertical type, possesses two fire motiths 
placed in the same axis, and no baking chamber. I have left 
out the latter on the ground of economy. I am thrxs obliged 
to do a special firing for the baking of pieces, but the construc- 
tion of a baking chamber would have made necessarj^ a raising 
of my studio and the expense of chimneys in the thickness of 
the walls. I lose on this account a certain amount of heat, 
which somewhat increases the time of firing, but the kdn being 
reduced to its simplest form does not need such costh^ repairs, 
and is easier both to repair and handle. 
When coming out of the fire mouth which is on a level 
with the floor of the kiln, the flame is violently thrown on a small 
waU M, cemented on both ends to the inside wall of the kiln 
and forming with it a segment of a circle (Fig. 47 and 48). 
This little wall being placed opposite the fire mouth, has a 
protective action, and besides it directs the flame, by stopping 
it and raising it toward the crown V (Fig. 47), from which it 
comes down between the saggar piles- to reach the opening O of 
the chimney C, through which it escapes. While passing througli 
the chimney, it strikes the oxAy damper P (Fig. 50) the function 
of which is to control it. The heat, being better distributed in 
the firing chamber, becomes more homogeneous through the 
more intimate mixture of the gases of combustion. There is 
only a dift'erence of about 20°C. between the top and bottom, 
so that the saggars do not suffer so much and do not need so 
much repairing and replacing. Three spyholes, two fixed ones 
R,R, and a movable one (that of the door), allow one to follow the 
phases of the firing on every side, by watching the Seger cones. 
'T->k: 
H0..49 
Foixr Au- to IS . 
YoKj^r a.u- Idois . 
Briq-iie relrnctn-ire, iirp brick. Lnhoratoire, &r\ng ehamher. lieton, de cailloitx, pebb\e foundation. Cavalier, fire mouth stopper. Regard, spyhule. 7yi<(U/i(/n, Ptiipppr to start Iho 
draft when lighting the kiln. Tvbe a covrant d'air tube for air draft on the level of bottom of firing chamliei-. 
