70 REPORT—1868. 
while the yield per charge of 483-3 lbs. of grey forge pig has been increased 
to 485 lbs. of puddled bar, as shown by the following return of a series of 
eighty consecutive charges in June last :— 
Regenerative Gas Furnace. 
TastE No. 3. 
Average 
per heat. 
No. of 
heats. Total charges and yields. 
Date. 
lbs. ewt. qr. lbs. Ibs. 
June 1868.| 80 | Pig iron charged.... 38,668=345 1 0] 483-3 
Puddled bar returned 38,808=346 1 25) 485 
Red ore for “fettling” 7,406= 66 0 14] 92:6 
proving that the yield of puddled bar slightly exceeds the charge of pig metal 
(representing a saving of fully 12 per cent. over the ordinary furnace), while 
the superiority of quality in favour of the gas furnace is fully maintained. 
It is also worthy of remark that these results are obtained regularly by 
the ordinary puddlers of the works, and that no repairs have been necessary 
to the gas puddling-furnace since November last, the roof being reported to 
be still in excellent condition. 
In these investigations I have confined myself to the puddling of ordinary 
English forge pig, in order to avoid confusion ; but it is self-evident that the 
same reasoning also applies, in a modified degree, to white pig metal or 
refined metal, the use of which I should not, however, advocate. 
Water-bridges.—Regarding the water-bridges, I was desirous to ascertain 
the expenditure of heat at which the saving of “ fettling” and greater ease 
of working was effected. The water passing through the bridges was accord- 
ingly measured by Mr. W. Hackney (who has also furnished me with the 
other working data), and found to amount to 251bs. per minute, heated 
40° Fahr. This represents 60,000 units of heat per hour, or a consumption 
not exceeding 8 lbs. to 10 lbs. of solid fuel per hour, an expenditure very 
much exceeded by the advantages obtained where water or cooling-cisterns 
are available. 
The labour of the puddler and of his underhand being very much shortened 
and facilitated by means of the furnace, I should strongly recommend the 
introduction of three working shifts of 8 hours each per 24 hours, each shift 
representing the usual number of heats, by which arrangement both the 
employer and the employed would be materially benefited. 
The labour of the puddler may be further reduced with advantage by the 
introduction of the mechanical “ rabble,” which has already made conside- 
rable progress on the Continent. 
By working in this manner, a regenerative gas puddling-furnace, of ordi- 
nary dimensions, would produce an annual yield of about 940 tons of bar 
iron, of superior quality, from the same weight of grey pig metal and the 
ordinary proportion of “ fettling.” 
In conclusion I may state that a considerable number of these puddling- 
furnaces have been erected by me abroad, and that in this country they are 
also being taken up by the Monkbridge Iron Company, Leeds, and a few 
other enterprising firms. 
The construction of these furnaces has been still further improved lately 
by the application of horizontal regenerators, to save deep excavations, and 
