Iron . 
127 
j immediately after this improvement, at the rate of 33 tons 
of iron per week, of as good quality as formerly ; for 
during this period, from the 21st of November, 1795* to 
July 30, 1796, this one furnace yielded 1188 tons of iron » 
No more coals were consumed in working the blast-engine, 
or other expences about the blowing machine incurred, 
and therefore no more power was employed to produce 
this great effect. It is also of much importance to re- 
mark, that the consumption of materials, from which this 
large produce was obtained, was by no means so great as 
formerly. The furnace required very considerably less 
fuel , less iron-stone , and less limestone , than were employ- 
ed to produce the same quantity of iron by the former 
method of blowing ; and according to the statements made 
out by the company’s orders, as great a change was effect- 
ed in the economical part of the business. 
From the success of this experiment, so well authenti- 
cated, and continued for several months, I am led to be of 
opinion, that all blast furnaces, by a proper adjustment of 
such machinery as they are provided with, might greatly 
and advantageously increase their produce, by assuming 
this as a principle, viz. u That with the given power it is 
j rather by a great quantity of air thrown into the furnace , 
i with a moderate velocity , than by a less quantify thrown in 
with a greater velocity , that the greatest benefit is derived \ 
in the smelting of iron-stones , in order to produce pig -iron 
However, it is by experiment alone, perhaps, that we can 
be enabled to find out the exact relations of power, velo- 
city, and quantity of air requisite to produce a maximum 
of effect.” 
Formerly in England as in this country, when charcoal 
was used, many of the furnaces were mere bloomer ies, 
worked by hand- bellows, or a small water-power. Then 
were introduced wooden drums, strongly hooped, with 
Barely valves or snorts, still very common in America, and 
