_ty off the gas, which is drawn out by means 
On the Blast presaantccamcce 99 
fuel used, is made to pass into a chamb unding tl 1 
outer part of the fire. Seetiny some idea of. which may be. formed 
by the representation in fig. 1. B, is the mouth of the furnace ; 
A A, gas chamber surrounding the upper part. ‘Fig. 1. 
of the fire room; D D, pipes connecting the ye 
fire room and gas sehen ber ; C C, pipes to car- 
of blowing cylinders and forced into the refi- — 
ning, puddling or other furnace, through a 
number of small orifices alternating with oth- 
er orifices, through which a cold or hot blast ~ 
of air is thrown, that serves to keep up the 
combustion of the gas when once united ; and 
by regulating the supply of air by means 
of stop-cocks, the maximum of heat can be obtained. In order 
to arrive at the maximum of heat, just sufficient air should be 
admitted to burn all the carbonic oxide and hydrogen contained 
in the gas coming from the blast furnace. If the amount of air 
be too small, some of the combustible gases pass out unconsumed ; 
if too great, the excess cools the furnace, and at the same time 
oxidizes the metals undergoing refining. The regulation of the 
supply of the blast is of the utmost nepertenes, and is said to be 
easy of accomplishment. 
The differences between the reverberating furnaces worked in 
this way and those in-which coal is used, is that carbonic oxide 
with a little hydrogen is the fuel, and it is burnt by a full supply 
of air. It is hardly necessary to say more of the advantages that 
are to arise out of this important change in the working of iron ; 
for there is no expense for fuel in the refining of the pig, as the 
gaseous combustible issuing from the mouth of the blast furnace 
is more than sufficient to refine all the pig made from the furnace. 
The quality of iron is also improved, as none of those impurities 
Contained in the coal and other fuel can interfere in the working 
of the iron.* 
The sooner these mot Bemsini ‘are introduced into our fur- 
haces, the sooner will ‘we be able to place iron in the market at 
@ price to compete with that coming from. any other quarter of 
— 
"IFT I mistake not, the Dufaur patent has been yee out in this country by Mr. 
Detmola, and has al already been applied to one or two furnaces.—J. L. 8S, 
bs 
{ST 
