It will have been noticed that only small amounts of iron can be refined at one time. This, indeed, has been the unfortunate part of wrought iron manufacture, for it may readily be seen that production of any such material in lots as small as a quarter ton results in labor costs which are almost prohibitive in these days of machine-made goods. Not only is the output of a furnace small but much skill and judgment are necessary for the production of a high grade product. Very sturdy and strong men, too, are required as puddlers, for the work is heavy and the extremes of heat and cold to which they are exposed necessitate men of rugged health. [Illustration: CROSS-SECTION OF A “SQUEEZER” ] This material in bar iron, engine stay bolts, butt and lap-welded pipe and certain other products has long held a high place. Though not as strong as steel, its very excellent welding properties and comparative freedom from “crystallization” and treacherous breakage under long continued vibration or sudden jar have fostered its application in such products as stay bolts, chain-links, cable hooks and others where failure might have serious consequences. Too, it is thought by many that pipes, sheets and other articles of wrought iron resist the corrosive influences of moist air, soil, etc., particularly well. The cinder films in which the fibers are supposed to be encased are given credit for such protective influence. [Illustration: “BOX PILES” READY FOR THE RE-HEATING FURNACE ] Though the product has always been a favorite with iron users, the industry has suffered during the last sixty years by reason of the high cost of manufacture, which has very largely restricted the application of wrought iron to certain uses for which first cost is not a main factor. The production of wrought iron rails has rapidly dwindled since the year 1880, when they began generally to be replaced by rails made from Bessemer steel. [Illustration: THE BALL GOING INTO THE “SQUEEZER” ] [Illustration: SHEARING THE MUCK BAR INTO SHORT LENGTHS FOR “PILING” ] [Illustration: THE BLOOM FROM THE SQUEEZER GOES TO THE “MUCK” ROLLS WHICH ROLL IT DOWN INTO “MUCK BAR” ] [Illustration: THE RE-HEATED “BOX PILES” BEING ROLLED INTO “SKELP” FOR PIPE, IN THE FINISHING MILLS ] [Illustration: CROSS PILING GIVES CROSS FIBERS IN THE FINISHED BAR—A DESIRABLE QUALITY ] Of recent years, mild steel has been the great competitor of wrought iron. With marvelous energy, skill, and much capital the manufacturers of Bessemer and open-hearth steels have adapted their products very well to the needs of the iron user, while the enormous tonnages turned out in short time by use of ingenious furnaces and other devices has resulted in a low cost of production. Had any of the several mechanical puddling furnaces devised for the manufacture of wrought iron proved really successful, things might be more rosy commercially for this very excellent material.