ar 
a oe 
* 
for the Smelting of Iron with Anthracite. 75 
concentrated fuel, the aniount of air thrown in must be much 
greater than when charcoal is used: Success, therefore, depends 
upon the quantity as well as upon the temperature of the blast. 
The necessary amount of “oxygen be secured only by 
means of the proper machinery, and a certain velocity. of the 
ast ; and in consequence of this fact, the false opinion that the 
ds ow antl upon the velocity or sharpness of the jet, 
-maintal In consequence of this view, the exit 
re sd to a small size, and the quantity secured by in- 
cremate 2 ocity under a high pressure; which much 
of the blast to be lost, as among the multitude of i sees he be 
air-tight, it is impossible to secure i 
the machinery is liable to injury fom the reat u essal 
strain upon it. 
_ The stack or main structure of a blast ate: is a ¢ 
ar , the lower portion of Wain - arch 
dd e of each side, leaving 
e€ fig. 1 
* 
Ac | an 4 2, See sn 
ee with the dousd square in fig. 1. ig circle in fig. 1, 
ind 
icates the internal face of the fire- Con lining (1, fig. 2) at its: 
widest part, and also the top of the bosh,* (, fig. 1, 2.) ~The li- 
ning being circular and the lower portion a square, the former is 
supported upon four plates (¢) of such a form as to close the an- 
pi of the la iter, and at the head of the furnace it is continued ¥ 
dinary | ickwork chimney, (2, fig. 3,) leaving one or two ; 
Sse ie spaces for the purpose of filling. The chief use of 
mney is to protect the workmen from the heat. g KS 
Lhe two p ior piers r passage (fig. 1, 2 
the admi issic Focal Vg lacs pipe, p, which descends from fe 
eur doy Sige ® at the head of the stack. . This passage. is some- ee 
times continued through the front piers, which renders the fre f 
ch, co oler, and gives more ready, access to the 
ig 18 a 
two 
