There has been no striking improvement in the manufacture of puddled iron, partly on account of the impression that it is doomed to be superseded by steel. Mechanical puddling has made but little progress, and few of the attempts to economize fuel in the puddling furnace, by the use of gas or otherwise, have been successful. I would, however, draw attention to the remarkable success which has attended the use of the Bicheroux gas puddling and heating furnaces at the works of Ougree, near Liege. The works produce 20,000 tons of puddled bars per annum, in fifteen double furnaces. The consumption of coal per ton of ordinary puddled bar is under 11 cwt., and per ton of “fer a fin grain” (puddled steel, etc.) 16 cwt. The gas is produced from slack, and the waste heat raises as much steam as that from an ordinary double furnace. The consumption of pig iron per ton of puddled bar was rather less than 211/2 cwts. for the year 1882; and that of “mine” for fettling was 33 lb. The repairs are said to be considerably less than in the ordinary furnaces, and the puddlers earn from 25 to 30 per cent. more at the same tonnage rate. I have already mentioned the large consumption, reckoned in tons of pig iron, of the materials for shipbuilding.
It may be useful to add that the gross tonnage of iron vessels classed during 1882 by the three societies of Lloyd’s, the Liverpool Registry, and the Bureau Veritas was 1,142,000, and of steel 143,000 tons, and that the proportion of steel to iron vessels is increasing from year to year. I am informed by our colleague, Mr. Pearce, of Messrs. Elder’s firm, that the largest vessel built by them in 1869 was an iron steamer, of 3,063 tons gross, with compound engines of 3,000 horse power, working at 60 lb. pressure; speed, 14 knots.
The largest vessel now on the ways is the Oregon, of 7,400 tons gross, and 13,000 horse power; estimated speed, 18 knots. The superficial area of the largest plates in the former was 221/2 square feet; that of the largest plate in the latter is 206 square feet. The Oregon is an iron vessel, but some of the largest vessels now being built by Mr. Pearce’s firm are of steel.
The information which I have obtained from Messrs. Thomson, of Glasgow, is especially emphatic as to the supersession of iron by steel in the construction of ships. They say that large steel plates are as cheap as iron ones, and that they have never had one bad plate or angle in steel. This is confirmed by Mr. Denny, who says: “Whenever our shipwrights or smiths have to turn out anything particularly difficult in shape, and on which much ‘work’ has to be put, they will get hold of a piece of steel if they can.”