AUTOBIOGRAPHY OF JOHN FRITZ 51
process, which is in use at this time, generaUy called puddUng.
The difference in the practice of to-day and that of fifty or more years ago is principally in what is called the fixing or Uning of that part of the furnace in which the iron is worked. In the old-time practice, called the dry or fer¬ menting process, soapstone was used for the lining, and only white or mottled pig metal was suitable. In the present practice iron ore is used. Phosphorus is the principal element that makes iron cold-short (a fact wliich at that time we did not know), and all pig iron contains more or less of it; consequently it was a most difficult task to get a pig iron that was right, and the only way we had of learn¬ ing was by experimenting, which was both troublesome and expensive. After succeeding in finding an iron that could be used successfully, another and unexpected trouble turned up. In making round iron for shafting and car axles, red-short pig iron was used. When we would change back to neutral iron for flat and square bars, we would find for a time that the neutral iron had become red-short. This was a surprise and caused great annoyance, expense, and delay. It was thought that the men who had charge of the pig iron had made some mistake, and had gotten the difi'erent irons mixed, but we could find nothing wrong there. Next the blast-furnace men were accused of using cUfferent ores, or hot blast, but they vigorously denied it. After a more thorough investigation it was found that the trouble occurred every time the change was made, and that the trouble righted itseU in a few days. This thoroughly satisfied us that it was not the fault of the pig metal but that the trouble was somewhere in the manipulation, and the only cause to which we could, in any possible way, attribute it was the cinder used in charging the furnace. Accordingly we had the cinder, made while puddling