ON PUDDLING IRON. 67 
protect the “fettling”’ (or oxide of iron used for lining the furnace) from 
being melted away. The overflow from one of the water-bridges is led into 
a sheet-iron tank below the bed, and then away. The evaporation from this 
tank keeps the bottom plates cool and preserves the cinder covering them 
from melting off, and the steam is carried away by a draught of air entering 
through two holes, 1, 1 (fig. 2), below the tap-hole, and passing off by small 
ventilating shafts, x, x (fig. 4), at the back of the furnace. 
A heating chamber, u (fig. 3), is arranged at each end of the furnace, in 
which the charge of pig iron may be heated to redness before it is introduced 
into the puddling-chamber, p p. 
The advantages of this furnace for puddling are, that the heat can be 
raised to an almost unlimited degree, that the flame can be made at will 
oxidizing, neutral, or reducing, without interfering with the temperature, 
that indraughts of air and cutting flames are avoided, and that the gas- 
fuel is free from ashes, dust, and other impurities which are carried into an 
ordinary puddling-furnace from the grate. In this last respect, the new 
furnace presents the same advantages as puddling with wood. 
The following Tables give the working results which were obtained from 
this furnace, as compared with the results obtained at the same time in an 
ordinary furnace from the same pig (the ordinary forge mixture). 
Regenerative Gas Furnace. 
Taste No. 1. 
Date. eda Time charged. | First ball out. ie a Yield. 
First shift. 
h. m. hs. ms: lbs. lbs. 
1867. 1 Si, Zo 6 32 410 392 
May 7. 2, 6 45 750: 433 396 
3 S5,-8 9 9 430 410 
4 9 15 LOY 7 AQ5 426 
5 10 20 hie 496 430 
6 11 40 12 46 A412 A412 
Second shift. 
af 1 48 2 AZ 428 410 
2 2 50 3 AT 420 414 
Ss 3 56 4 53 426 418 
4 on 0 Gago 432 A417 
5 6-5 t 72 425 407 
6 7 20 8 15 420 422 
Third shift. 
1 9 10 10 15 493 414 
De 10 25 11 30 4292 412 
3 11 35 12 40 420 420 
4 12 45 2" 430. 410 
5 2 10 3 10 424 418 
6 3 16 4 20 420 400 
