19 
AN ESSAY ON THE EFFECTS OF AQUEOUS VAPOUR IN THE 
ATMOSPHERE, AS APPLIED TO BLAST FURNACES, IN THE 
MANUFACTURE OF PIG IRON.* 
BY HENRY LEAH, ESQ., OF BYERLEY HALL. 
It is now upwards of five years since you formed yourselves 
into an Association, not merely to discuss topics relative 
to the regulation of your concerns as iron-masters, but also, 
to make a reciprocal communication of your several expe- 
rience in the art of smelting and manufacturing iron, through 
all its different branches : that a more perfect knowledge 
thereof might be promoted, and the certain advantages re- 
sulting therefrom obtained. 
To accomplish this desirable object, it was well proposed 
by your then president, (Mr. Dawson,) that essays should be 
written by each member in rotation ; and questions proposed 
for discussion upon subjects relating to the art, at each 
quarterly meeting : and it was with much pleasure we wit- 
nessed your president follow up his proposals with an intro- 
ductory dissertation, furnishing hints abundantly sufficient to 
ground essays upon, from that period to the present ; and also 
with a copious, entertaining and instructive essay upon the 
effect of air and moisture upon Blast Furnaces : in which he 
evinces at least a disposition of inquiry highly commendable, 
and gives an example of industry and perseverance in observ* 
ing, collecting, and arranging facts, well deserving the grati- 
tude of every ironmaster. 
From that author's well known abilities, opportunities, and 
other ample, and more than ordinary sources of information, 
any opinion he may adopt certainly assumes a very imposing 
authority ; and it is therefore with much diffidence, that we 
venture to differ from him in our views of the effect of air and 
moisture upon blast furnaces. 
* This Essay was originally intended for, and addressed — " To the Society of 
Iron Masters of the Counties of York and Derby ;" and was delivered at their 
Quarterly Meeting held at Bradford, June, 1805. 
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