874 Description of a Patent Blowing Machine. 
machinery are so contrived to work, that at the moment when 
the one is at the poise, or in the act of recovering itself after the 
expulsion of the air, the other shall be in the full energy of its 
operation. It is thus by the double blowing machine that a 
powerful and invessant blast is maintained. 
The advantages of this machine in point of power, the saving 
of fuel and labour, and in the more complete and speedy re- 
duction of the ore, are such, that it is found incomparably su- 
perior to the usual method of exciting an intense heat, and it is 
now coming into general use. Indeed its adoption is a matter 
of course; for it appears from the report of those who have tried 
it, that the manufacturer is enabled to work 40 per cent. cheaper 
than he can without it. The prodigious strength of the blast, 
and the rapidity with which the metal is reduced, are perfectly 
astonishing to the founder in his first experiment with it. L 
have seen several letters which Mr. Street has received from 
different manufacturers who have used it,~and from the lowest 
statement it appears that the power of one man will melt at a 
eupola 5 cwt. per hour; and several have said that 8 ewt. may 
he fused in the same period of time. One founder computes 
that he can with one horse melt more metal in eight hours, than: 
he could do before with three horses in twelve hours. In fact, no= 
thing can be stronger and more decisive as to its advantages, than 
the testimonials which have been received from all quarters; and 
ean it may not be too much to sav, that a discovery more 
eneficial tothe manufacturer has not taken place since the inven- 
tion of the steam-engine, the master-piece of human ingenuity. 
The annexed figure represents the front end of the engine 
and its connexion with the supporter ; and if we suppose the end 
to be made of glass, we should have a view of the interior, such 
as I have represented. 
Fig. 1. Working Handle. 
—— 
\ 
This trunk is SWaterSjZ= 
made of copper, 
and is fixed over SSS 
the valves aa, 
: Tiga 
fig. 1. Its point 
= ID 
and conveys the air to the blow-pipe. 
cc show the di- 
rection of the par- 
tition plank; DD 
the supporters. 
B corresponds pr = 
with the centre of the machine, 
