shire, England, made very important improvements in the construction of puddling-furnaces, by substituting iron plates for the original sand bottoms of their puddling-chambers; and in the 
Fig. 23.—Plan of an Early Puddling-Furnace. conduct of the process, by using iron-ore as the chief source of the oxygen necessary to decarburize the melted pig iron. This ore was packed around the sides of the interior of the furnace, and the bottom plates were protected by a layer of oxide of iron. These improvements more than doubled the daily production from a furnace, and at the same time a superior quality of iron was made.
Mr. Rogers encountered a great deal of ridicule in attempting to introduce these improvements, which were pronounced impracticable and of no value by many of the leading iron-masters of England; and, as he failed to protect his rights by patents, the only reward that he ever received for inventions that have been of vast benefit to mankind was the nickname "Old Iron Bottoms" which was bestowed upon him by those of his contemporaries who fully believed that they had become possessed of all desirable knowledge, and were, in fact, too wise to learn. Unfortunately for our country, a few of the descendants of these wise fools, who were patriotic enough to "leave their country for their country's good," found their way to America, and are honoring their ancestry by sneering at all ideas and methods that are not hoary with antiquity and moldy respectability. In spite of such counsels in the past, the improvements of Mr. Rogers found their way into use in America and the world at large, and for the last fifty years there has not been a puddling-furnace as originally constructed by Cort in existence.
A very good idea of the appearance and construction of the puddling-furnace in common use in the "puddle-mills" of England and America is conveyed by Figs. 24 and 25. Fig. 24 is a side elevation of the furnace, whose interior form is shown by dotted lines. The whole of the brick-work is inclosed in a casing of cast-iron plates, securely bolted together. The door of the working-chamber is seen in the center (and at C, Fig. 25), counterbalanced and operated by a lever and chain, and below it the "tap-hole," by which the "cinder" made in the process is "tapped off"; to the left is seen the "stoke-hole," and just to the right of it is shown, in dotted lines, the outline of the "bridge-wall" separating the "fire-box" on the left from the "working-chamber" in
