CONSTRUCTION OF LIME KILNS—BURNING LIME. 
345 
CONSTRUCTION OF LIME KILNS—BURNING LIME. 
The form of lime kilns vary; some being 
constructed inside in the shape of a hogshead, 
or of an egg, opened a little at each end, with 
the diameter at the bottom small, gradually 
widening towards the middle, and then con¬ 
tracting again towards the top; while others 
are made in the form of a sugar loaf, with the 
small end down; others, again, are of an ob¬ 
long oval in the ground plan, as well as at the 
middle and top. The first of these forms is 
most generally in use, and when the sides are 
nearly perpendicular, it is observed that less 
fuel is necessary, in consequence of the great 
degree of heat which is created, above that 
which occurs in kilns formed in the shape of a 
Lime Kiln.—Fig. 84. 
sugar loaf reversed. Near the bottom of large 
kilns, two or more openings are made for ad¬ 
mitting the air necessary for supplying the fire 
and for dragging out the lime after it is burnt. 
Lime kilns may be built either of stone or 
bricks; but the latter are considered preferable, 
particularly for the inside lining, as they are 
better adapted to stand a high degree of heat 
They should always be situated at, or near, the 
quarry, and if possible, in the side of a cliff or 
bank; or they may be furnished with a “ ramp,” 
or inclined plane, of earth or stone, for carting 
up the fuel and limestone to their tops. 
A kiln of approved construction, suitable for 
burning lime with coal, or other dry, smokeless 
fuel is denoted by fig. 84. It is supposed to be 
built on the side of a bank or cliff, of a circular 
form within, 32 feet high from the iron grating 
over the pits, three feet in diameter at the top, 
and seven feet across, near the middle, at a 
point eighteen feet above the grating. The 
walls are designed to be built of stone, from 
three to six feet thick, and lined with bricks. 
Below the shaft, or hollow of the kiln, are two 
arches, or pits, each three feet wide and three 
feet high, divided by a partition wall eighteen 
inches thick, extending up the shaft ten feet. 
About eighteen inches from each arch, or pit, is 
an oven, say two and a half feet square, 
where coal is used for fuel, and some¬ 
what deeper, where wood is employ¬ 
ed, communicating with the shaft by 
narrow flues. Below the shaft, are 
two moveable iron grates for dragging 
out the lime after it is burned. The 
ovens, as well as the arches under the 
shaft, are provided with iron doors, 
which are to be closed whenever it 
is desired to stop the draft. An iron 
cap, or cover, is also provided, to be 
placed over the top of the kiln, to pre¬ 
vent the escape of more heat than is 
necessary to keep up the combustion 
of the fuel. This cap is also fur¬ 
nished with a damper, or valve, for 
regulating the draft. 
In a kiln like that described above, 
it is obvious that the lime can be well 
burnt, with a comparatively small 
amount of fuel, in winter as well as 
in summer, and tha A the farmer or 
others can be supplied with lime, at 
any time, without extinguishing the 
lire. All that is necessary to be done, 
is, to supply the broken limestone, or 
shells, and the fuel at the top of the 
kiln, and rake out the burnt lime 
through the iron grate, or opening, at the 
bottom, as fast as occasion may require. 
In case it may be necessary to check 
the burning for a time, nothing more 
is necessary than to close the iron 
doors at the bottom of the kiln, and the 
cover, or cap, at the top, when the fire 
may be kept alive for four or five 
days. 
When the kiln is to be filled, the 
limestone should be broken into pieces 
about the size of a man’s fist, and laid in alter¬ 
nate layers with the coal, usually in the pro¬ 
portion of three of the former to one of the 
latter; but, as limestones vary much in their 
character, the proper quantity of fuel can only, 
be regulated by trial. The coal should not be 
placed nearer the lining of the kiln than eight 
or nine inches, in order not to melt nor burn 
the bricks. 
The class of lime kilns in common use, in the 
United States, are similar to that of Mr. Ward 
