 thamber, and both are conducted through passage outlets at one end of - 
_ the furnace, where mingling, they burn, producing the heat due to their 
_ chemical action. Passing onward to the other end of the furnace, they 
{i.¢, the combined gases) find precisely similar outlets down which they 
_ piss; and traversing the two remaining regenerators from above down- 
ward, heat them intensely, especially the upper part, and so travel on in 
- their cooled state to the shaft or chimney. Now the passages between the 
_ Surregenerators and the gas and air are supplied with valves and deflect- 
ing plates, which are like four way-cocks in their action; so that by the 
® which enter the stack to be cast into the air are not usually above 
When the furnace is in full order, the heat carried forward to be 
ved by the chemical action of combustion is about 4000°, whilst that 
back by the regenerator is about 3000°, making an intensity of 
Powel which, unless moderated on purpose, would fuse furnace and all 
its action 
< us the regenerators are alternately heated and cooled by the out- 
g and entering gas and air, and the time for alternation is from half 
oir to an hour, as observation may indicate. The motive power on 
ki i 
iddlig, ; and if a rapid evolution of heat is required, as in a short 
, rile” furnace, the mouth of the gas inlet is placed below that of the 
‘the 1) If the reverse js required, as in the long tube-welding furnace, 
fumace > .*'Tangement is used. Sometimes, as in the enameller’s 
bac’: Which is a long muffle, it is requisite that the heat be greater at 
kee” the muffle and furnace, because the goods, being put in 
Out at the same end, those which enter last, and are withdrawn 
pee 
