Like everything else in the world of iron and steel, these blast-furnaces have undergone revolutionary improvements during the past quarter of a century. From being most dangerous and destructive structures causing frightful loss of life and producing only about one ton of iron a day for every man working about them, as formerly, they have now become relatively harmless monsters, capable of turning out six times that quantity of ore for each man employed. The older blast-furnace was a huge, chimney-like structure, perhaps a hundred feet high, into which the ore, coal, and limestone were poured. Most of the work about these furnaces was done by manual labor, or at least manual labor was an active assistant to the machinery used in manipulating the furnaces. The top of the furnace was closed in by a great movable lid, or "bell," and the material for charging it was hauled up the sides by elevators and dumped in at the top. About the top of the furnace was constructed a staging upon which the workmen stood, an elevator shaft connecting the staging with the ground. The ore and other materials were brought to the foot of the shaft on cars from which it was shovelled into peculiarly designed wheelbarrows, trundled to the elevator, and hauled to the top. In order to dump the wheelbarrow loads into the furnaces it was necessary to raise the bell. This was always dangerous, and frequently resulted in the suffocation or injury of the workmen on the staging. For when the bell was raised there was an escape of poisonous gases, which might flare out in a sheet of flame, with the possibility of burning or suffocating the workmen. The fumes from these gases, if inhaled in small quantities, might simply cause coughing, hiccoughing, or dizziness; but when inhaled in large quantities they struck down a man like the fumes of chloroform, suffocating him in a few seconds if he was not removed at once into a purer atmosphere. Indeed, the likelihood of this was so great that at many of these furnaces a special workman was detailed to take the position on the staging, well out of range of the gas, his sole duty being to rescue any of the men who might be overcome, and hurry them as quickly as possible down the elevator shaft into the pure atmosphere below. It was not an uncommon thing in the neighborhood of these older furnaces to see stretched about on the ground at the base several workmen in various stages of suffocation. Fortunately, by use of precautionary measures, fatal accidents were rather unusual, the men being overcome only temporarily, and usually recovering quickly and returning to work.