On the Produétion of Caft Iron, &e. 325 
ftill reigns there; and that the curious manipulations of thefé 
regions are ftill fhrouded with error and mifconception 5 as 
if Saher dingy ftruéture forbade the entrance of genius, or 
configned her laborious unlettered fons to an endlefs ftretch 
of pacha obfeurity ? 
The plate of the blaft-furnace, given in the preceding 
Number, having a full defcription appropriated to it, I fhall 
proceed to detail the train of preparation neceflary before the 
furnace is brought to produce good melting iron. 
The furnace belting finifhed, the bottom “ail fides of it, iw 
two feet up the {quare funnel, receive a lining of common — 
bricks upon edge, to prevent the ftone from fhivering or 
mouldering when the fire comes in contaét with it. On the 
front of the furnace is ereéted a temporary fire-place, about 
four feet long, into the bottom of which are laid correfpond- 
ing bars. The fide-walls are made fo high as to reach the 
under-furface of the tymp-ftone ; excepting a {mall fpace, 
which afterwards receives an iron plate of 1! inches thick- 
nefs, by way of a cover: this alfo preferves the tymp-ftone 
_from any injury it might fuftain by being in contaé with the 
flame. A fire is now kindled upon the bars, and is fed occa- 
fionally with {mall coals. As the whole cavity of the furnace 
ferves as a chimney for this fire, the draught in confequence 
is violent, and the body of heat carried up is very confider- 
able. In the courfe of three weeks the furnace will thus 
become entirely free from damp, and fit for the reception of 
the materials: when this is’ judged proper the fire-place is 
removed, but the interior bricks are allowed to remain till 
the operation of blowing commences. Some loofe fuel is 
then thrown upon the bottom of the furnace, and a few baf- 
kets of cokes are introduced; thefe are allowed to become 
thoroughly ignited before more are added. In this manner 
the furnace is gradually filled; fometimes entirely full, and 
at other times 5-8ths or 3-4ths full. The number of baf- 
Kets full depend entirely upon the fize of the furnace: that 
in the plate will contain goo bafkets. If the coal is fplin 
the weight of each bafket-full will be nearly 110lb.x 
_ g00=99,000lb. cokes. As this quality of cokes is made 
with a lols of nearly 50 per cent, the original weight in raw 
4 coals 
