ON THE ADVANTAGEOUS USE OF A GASEOUS ESCAPE. a7 
is not sufficient to ensure a passage of air through the grate, I was obliged to 
use for the stoves coal of a rubbly size, and consequently of increased cost. 
In this way | found the charge on the ton of iron, of heating the blast, very 
onerous, as compared with other districts where larger quantities of iron per 
furnace are made, and where the small of bituminous coal is used for the heating 
ovens. Fortunately, in my attempts to use the escape from the tunnel head 
heat my blast of air, I neither made my apparatus part of the furnace, nor 
d I attempt to burn the gases. I built my stove alongside the furnace, of 
which however it forms no part, and by means of a stack about 25 feet higher 
than the top of the furnace, I was enabled to draw into it as much of the 
heated air and flame as I required. The result of this plan has been a most 
perfect success, from its thorough simplicity. I interfere in no way with the 
perations of the furnace ; everything is as before; my apparatus is merely three 
or four horizontal flues of about 12 inches diameter, constructed about 3 feet 
below the top of the furnace and leading into an adjoining chamber or stove, 
provided with a stack which makes the draught. Into this stove I am enabled 
to draw as much of the gaseous escape as I require, and by means of a damper 
on the stack (what is equally important), as little as I choose. The quantity 
squired to produce hot-blast for a furnace is very little, not being more, as 
ar as I can judge, than one-sixth of the quantity passing off the tunnel head. 
LT attempt no combustion of the gases, for as they rise from the furnace and 
enter the stove with a temperature of about 1800 degrees, and leave it ata 
“temperature of about 800 degrees, whilst all the heat I require for the blast 
is about 600 degrees, the mere passage of them, as heated vapours through 
‘the stove, gives me all the temperature [ want; whilst having no combustion 
foing on, the pipes remain uninjured, the bricks unmelted, and the apparatus 
ways effective. My reason for thinking there is little combustion of the 
ses at 3 feet below the surface of the materials is, that when the vapours 
ass through the stove and reach the top of the stack, where they come in 
ntact with the atmosphere, there bursts out a bluish flame, visible at night, 
ich is speedily extinguished from a reduction -of temperature below the 
nt at which the mixed gases burn. When, on the contrary, I allow the 
terials in the furnace to fall below the mouths of the flues, a combustion of 
ie gases takes place previous to entering the stove, and the vaporous appear- 
nce disappears. Looking at the perfect simplicity of the arrangement, | think 
May warrantably boast that this plan is equal in simplicity and in cheapness 
the supply of hot water from the boiler at the back of the kitchen grate. 
Plate II., with the references, will explain the details of the arrangements 
‘Ystalyfera. 
‘Cross section through furnace and heating stove, showing— 
56. Flues from furnace to stoves. 
’ ¢. Hot air chamber, containing— 
bd. Upright hot air tubes. 
acks which create the draught and draw the gases through the flues 2 2 into the hot 
air chamber. 
lampers on stacks, to regulate the supply of heat from the furnaces into the hot air 
chambers. 
Cross pipes, on which the upright hot air tubes are fixed. 
‘Side pipes, conveying the blast to the cross pipes. 
Jpeast pipes, conveying cold air to the stove. 
Owncast pipes, conveying heated air to the tuyéres. 
iM doors, by opening which the draught is reversed, and the hot air chamber cooled 
down. 
ofs over heating chambers. 
orizontal section of heating chambers and flues. 
ertical section through heating chamber and stack. 
