76 REPORT—1848. 
burning material ; but in all cases the contrivance formed part of the furnace 
itself. All these several obsolete plans are shown in the drawings of an ela~ 
borate work on Hot-Blast, published officially at Freiberg in 1840, which i 
contains drawings of all the different apparatus that have been known in — 
England, Wales, Scotland, Belgium, Germany, and Sweden. The fatal objec- — 
tion to these plans for heating the blast was, that in case of derangement of — 
the apparatus, the operations of the furnace had to be suspended during re- 
pair ; and even according to several of the schemes, it would have been neces- 
sary to blow out the furnace itself, and take it down in order to repairaleaky 
joint. These attempts were speedily relinquished, and I am not aware that 
any plan of the kind is in operation in the iron trade abroad, certainly not in 
this country. Another series of attempts took an opposite direction. The — 
top of the furnace was either partially or wholly closed, except during char-_ 
ging; the gases were thus collected and carried to a reservoir or gasometer; 
they were passed through water to be cooled and purified ; air-pumps were 
employed to force them towards the point, where they were afterwards to be 
burnt in a gas furnace. Several patents have been taken out for this appli- 
cation, the first as early as 1838, but, although tried in various works, I do 
not know that any plan of the sort is in use in this country. It was found 
that the combustible gases collected from the furnace were so diluted with 
nitrogen (itself incombustible and incapable of supporting combustion), that — 
it required two conditions to burn them in so mixed a state :—Ist. That a blast 
of air should be employed... 2nd. That such blast should be heated. When - 
once ignited, the heat produced by these gases, consisting of carbonic oxide 
and hydrogen partly in combination with carbon, is intense, so much so, that 
the tops and sides of the gas-furnace were speedily melted down. Still, if this 
plan of consuming the gases to produce heat, instead of being directed to 
stoves and boilers, had been employed as abroad, to carry on the processes of — 
converting pig-iron into malleable iron, which require a very high tempera- 
ture and a steady fire, with a limited admission of air, I think practice would — 
have perfected the details and conquered the obstacles ; but in this country of © 
cheap fuel, the gases being ignited merely to heat the blast or to raise steam, — 
requiring only a temperature of melting lead and boiling water, and for pur- 
poses where a high temperature cannot be employed without danger, it was 
found a fatal objection that a blast machine had to be provided, and a hot- 
blast apparatus kept at work to impart the necessary temperature for the gas — 
furnace ; thus of course reducing, and in fact destroying, all the saving to be ~ 
effected, besides complicating the operations of the furnace by additional” 
q 
machinery and apparatus. 
This want of simplicity has led to the abandonment of the gas-furnace in— 
this country as a means of consuming the vapours escaping from the tops of — 
blast-furnaces. At this point I found the subject, when four years ago my 
attention was attracted to it. Truly necessity quickens invention, and but 
for an obvious difficulty under which I laboured, I fear I also should have 
allowed the huge volumes of flame and vapour to pass off as heretofore un- — 
heeded. But I laboured under two serious disadvantages at Ystalyfera in 
employing the hot-blast. First, as the furnaces working on anthracite coal 
cannot be made to drive like coke-furnaces, although they burden heavily, the 
make is only 50 or 60 tons of iron per furnace weekly, and falling on this — 
small weekly quantity, I had the cost of the hot-blast apparatus, consisting of 
three stoves or heating furnaces, consuming about 35 tons of coal together a 
week, and requiring the attendance of two men, one by day and one by night; 
next, as the small or slack of anthracite coul burns very imperfectly in a re- 
verberatory furnace from its not caking at all, so that the draught of achimney 
1 
