j yj. Dr. Beddoes on fame Appearances attending 
for this purpofe he ufed fometimes an iron lever, and fome- 
times a kind of hoe; but he firft turned the flame from off 
the metal, which is done by letting down a damper upon the 
chimney correfponding to that with which ordinary reverbera- 
tory furnaces are provided, and by raifing the damper of a 
fecond chimney, which proceeds immediately from the fire- 
place, and carries off the flame, current of air, &c. without 
allowing it pafs into the body of the furnace. 
In 50 minutes from the commencement of the operation, 
the metal had become in confequence of the conftant ftirring 
loofe and incoherent ; it appeared about as fmall as gravel; it 
was now alfo ftiff, and much cooled. 
55 m. from the fame period, flame turned on again. Work- 
man keeps ftirring and turning over the metal ; in 3 m. it 
becomes foft and femi-fluid ; flame turned off ; the hotteft part 
of the mafs begins to heave and fwell, emitting a deep blue 
lambent flame. The workman calls this appearance fermen- 
tation. 
1 hour 1 m. blue flame breaking out over the whole mafs ; 
heaving motion alfo general. 
1 h. 13 m. metal full as hot, or, as the workman and my- 
felf both judged, rather hotter than at the inftant the flame 
was turned off, though it is now a quarter of an hour fince. 
1 h. 18 m. where there is no heaving and no blue flame 
the mafs is fenfibly cooler, and only of a dull red heat. 
1 h. 20 m. workman obferves, that the metal fticks lefs to 
his tools. Pig-iron, he fays, faftens upon it immediately, and 
muft be (haken off by ftriking the other end with an hammer ; 
as it approaches more and more towards nature (malleable 
iron) it adheres lefs ; and when the tools come clear up out of 
the mafs, he judges it to be fermented enough. 
~ 1 h. 
( t . . ■ ' 
I 
