Page:Popular Science Monthly Volume 38.djvu/166

154 "Formerly furnaces were constructed much simpler, and no specific or exact proportions were observed; and it was not considered necessary that the walls should have any fixed dimensions, either as to thickness or height; but (according to Agricola, who was the first to describe them) the whole structure was rude,



loose, and imperfect, their daily product of iron was small, and they consumed a very large quantity of charcoal; but afterward, when it became evident that regularity in smelting insured excellence of product, and at the same time the realization of