RERAMIC STUDIO 
229 
As ill the coal kiln, the chimney is braced with corner 
l:)ands bolted together, two feet apart from each other. The 
Ih-e mouths are solidly braced with iron (fig. 91) and the kiln 
is strongly circled, the bands being | of an inch thick and 20 
inches wide. They rest on two iron supports 2| inches wide 
and li inches thick. The construction is made exclusively 
of fire bricks, brand J.B., cemented with a cement called in 
French coidis and made of 
Earth of Provins pulverized 20 
Grog of pulverized saggars 80 
This coulis is sold by Mr. Ducouroy, Ivry-Port, Seine. 
The damper is placed so that it can be reached by hand, 
being about 3 feet from the ground. 
The most regular of the Sevres kilns, an elevation of which 
are in .4 and they join each other in the baking chamber 
through the openings B. Each chimney has a special damper 
C acting directly on each fire mouth. Here the small wall D 
is circular. The baking chamber E ends in a vault pierced 
with many square holes F, through which the flame enters the 
central circular chimney G. 
In vertical kilns the pressure of the gases of combustion 
against the inside walls of the kiln, is such as to make it nec- 
essary to use strong iron bracings, to enclose and strengthen 
the outside masonry of the kihi and prevent its bursting. 
Besides, in order to protect the construction against injuries 
by humidity, a small vaulted room has been built under the 
Iciln in I". 
The cost of this Sevres kiln is about $1,600, but its con- 
struction is of the best in regard to accuracy, solidity and even 
elegance. In opposition to this, I can give the details of the 
cost of my kiln, the figures of course applying to material 
bought in Paris: 
Construction 
Fr. 
984,85 
Material 
" 
425.30 
Iron braces 
458,65 
Fr 
1,868,80 
I give (fig. 51), in order to emphasize the simplicity of mine, is 
built of J.B., has three fire mouths H, three chimnej^s R, con- 
structed in the walls of the kiln; their three rectangle openings 
or in round figures $400. 
Each firing consumes from 5 to 6 sfercs (cubic metres) of 
wood, equivalent to I J to if cords, or on the average l^ cord, 
the cost of which in Paris is about $24. The expense for labor, 
various materials, etc., being on an average $40, brings the 
total cost of one firing to about $64. 
The kiln can hold 80 pieces of medium size. After three 
firings repairs to the average amount of S6 are necessary. 
Contrary to kilns with up draft, the temperature is higher 
at the top than at the bottom of the kiln. 
As will be seen the cost in construction and fuel for such 
a kiln is far above that of the first kiln, and one will easily 
understand the reasons which made me adopt coal for niv 
trials, notwithstanding the injurious effect of this fuel on 
decorated pieces. 
There is an innovation which I will mention, although it is 
somewhat outside the limits of these articles, the adoption by 
the porcelain industry of gasogene kilns, the kilns of the future. 
Glassmakers and metallurgists have already derived great 
profit from these kilns which have the great advantage of 
economy in fuel and regularity in firing. If they are not more 
general^ used for porcelain, it is due to the very large expense 
of installation. However a gazogene kiln is in use in Berlin, 
and another, of the Siemens type, has been established in 
Limoges and has given good results. The fuel is peat. The 
great economy in firing is due to the fact that the heat can be 
controlled at will, and that the reducing atmosphere can he 
instantaneously changed into oxidising, and vice versa. 
The conclusion of this article is that those who have only 
limited resources, and are not expert ceramists, wUl do well to 
limit their expenses to the cost of the small coal kiln, the fire 
mouths of which, at the end of the trial period, can be trans- 
formed at a small cost into fire mouths for wood. But those 
who have sufficient resources, can avoid this trouble, by adopt- 
ing from the beginning the plans of my wood kiln, to which they 
may add, if wanted, a baking chamber, keeping the same 
measures but having the chimneys built in the wall itself. 
r If 
SHOP NOTE 
We have received an interesting catalogue from James 
Hall of Philadelphia. Besides the list of materials it contains 
much practical instruction for their use. 
