43 
duce of the furnace was exceedingly deteriorated. He men- 
tioned this fact, in order that some experiments might be 
made, or at least in the hope that some gentleman would 
favour the meeting with his opinions on the subject. It was 
found the production of furnaces might, from the causes he 
had mentioned, be injured to the extent of 1 5s. or £1 per ton. 
Practically, he had known this loss frequently, and, indeed, the 
fact was well known and admitted by every man interested in 
the iron trade. If, then, this deterioration occurred on the 
produce of one furnace, they might very easily see that, in 
this country, where considerably above one million tons per 
annum was made, a very serious injury might be sustained. 
Dr. Alexander, of Halifax, said — He thought the ques- 
tion under discussion was one of considerable interest, from 
their being in the vicinity of many great iron works in active 
operation. With respect to the opinions which Mr. Leah had 
offered, he had certainly made out a priority of claim to the 
substitution of hot air for cold in blast furnaces. He (Dr. 
Alexander) had previously imagined that it had been a recent 
and modern improvement, but if he understood Mr. Leah 
correctly, that gentleman, thirty-five years ago, was per- 
fectly satisfied that air, heated above the ordinary tem- 
perature, would materially aid the consumption of the fuel 
and the dscomposition of the iron stone. It must be very 
flattering to Mr. Leah to find that his opinions were con- 
firmed, and that the hot air blast was very generally intro- 
duced. He had an opportunity two or three days ago, of 
seeing over the Low Moor Iron Works, accompanied by Mr. 
Lamplugh Hird, and he found that the hot air blast was not 
introduced there. He was told it had been used for a while 
at Shelf, and the production was considerably increased, but 
it was subsequently abandoned under the conviction that it 
did not equal in quality what they had been accustomed to 
produce. With respect to aqueous vapour, he could easily 
believe that it would reduce the temperature : if, for example, 
