CHAPTER XXVI. FORGE AND ARMOR-PLATE PLANT.
After the failure to get the company to go into the manufacture of structural material and the plate business, I concluded that it would be well to give them time for consideration before making any further suggestions. Some one or two years later I caUed the company's atten¬ tion to the fact that there was not a forge plant in the country where a ten-inch shaft could be properly forged. The heaviest hammers that were in use for forging were of about ten or twelve tons, but they were entirely too Ught for heavy forging. In order to make the blow more effec¬ tive, steam was used on the top of the piston, which for forging heavy shafting was worse than useless, as the blow is so quick that the center does not receive the full force of it, and the tendency is to create longitudinal seams and circumferential cracks; the center, not receiving the full force of the blow, is in a measure elongated by the tension of the outer portion of the shaft. Knowing this to be the fact, I did not use either wrought-iron or steel shaftmg that was forged under a Ught hammer, but always, where great strength was required, used air-furnace castings made out of the best cold-blast charcoal iron that it was possible to get, and in my long experience I never had one fail. In some instances, where iron forgings failed we replaced them with air-furnace castings, and they gave no trouble.
I have known wrought-iron forged shafts to fail and be replaced by cast-iron shafts which never gave any trouble, and a person giving the subject any serious consideration wiU see at once why a cast-iron shaft should be safer and