Uuw to establish a Tile-Yard. 
469 
and being protected bv banks on three sides, and the burner s 
shed on the fourth, is not subject to injury from the weather. 
When the situation will permit (as in nine times out of ten it 
will), it is much the best plan to sink the kiln under<;round. The 
drawings show the kdns 7 feet underground and 9 feet above. 
The three outside walls built of brick must be 18 inclies thick; 
the centre wall, 2 feet thick, between the kilns. If the kiln 
be built of stone, it will require a 4\ inch lining of brick 
thoroughly tied into the stone-work ; the stone wall being 20 
inches thick. 
If built of Norfolk lumps, or what is termed in Devonshire 
cobb, it must be lined with brick in the same way, and the clay 
wall made 30 inches thick ; b b shows the head wall, in which are 
two openings or hatchways, c c, 3 feet wide, open to the top of 
the kiln, and below the ground ten fire-holes, 3 feet by 1, 
arched at the ti^p and at equal distances, commencing at 9 inches 
from the internal side of the kiln, and having 18 inches between 
each, thus making a total of 12 feet 6 inches. 
The fire-holes are enclosed by doors d d, 18 inches by 
12 inches, and the under 18 inches are for draught, and left open 
to scrape out the cinders. 
The head wall is built 3 feet 6 inches thick, 4 feet high from 
the foundation, to prevent, if possible, the waste of any tiles from 
too rapid burning ; above this height it gradually decreases in 
thickness to the top, which is the same as v a. The beaiing bars 
may be of wrought-iron, 18 inches long, 2^ inches by i inch, which 
are firmly fixed 2 feet 6 inches apart in the fire-holes, 18 inches 
from the bottom, which allows a clear area of 18 inches by 12 inches 
for the draught and cinder holes. These draught-holes will extend 
from the head to the opposite wall, entirely through the kiln. 
On the bearers are placed the long bars of wrought-iron, 14 feet 
3 inches long, 2^ inches by ^ inch, four in each fire-hole, with a 
nail between each to prevent them from melting together. I may 
here remark that bars of wrought-iron * answer better than those 
of cast-iron, and are far cheaper. The benches are built 18 
inches thick between each fire-hole the whole length of the kiln, 
and are carried up 2 feet 6 inches, which is the height of the rise 
* Wrought-iron bars do not cost one-third the price of cast-iron, in 
consequence of the immease weight of the latter. They are found to last 
quite as long ; and in case of their becoming burnt up, each bar being the 
whole length of the fire-hole, a new one is easily substituted without dis- 
turbing the rest. The time that bars last entirely depends on the fireman ; 
I have seen both binds nearly destroyed in two seasons from neglect — 
wrought iron will generally last 10 or 12 years. 
