AUTOBIOGRAPHY OF JOHN FRITZ l8l
the outside more rapidly than the interior), the imperfec¬ tions, whatever they might be, being the weaker parts, were drawn more rapidly than the more perfect parts of the ingot, consequently the imperfections were greatly aug¬ mented.
Mr. Durfee once read a paper before the Franklin Insti¬ tute, on the conditions which cause wrought iron to be fibrous and steel low in carbon to be crystalUne, and a most admirable paper it is, and one which every maker and user of steel should read and study. In regard to unsound ingots, he says it is a common opinion that one of the reasons why steel forgings are often found hollow in the interior is the failure to work them under a sufficiently heavy hammer, but no hammer can do more than aggravate the evil of internal ruptures in ingots of steel. Tins is weU said, and a truth that caimot be gainsaid. It was imperfect ingots, lack of knowledge in heating and forging, and also the want of skiU to treat the forgings properly after they were made, that caused so many failures in steel forgings only a few years ago, and caused many people to think and believe that there was some mysterious uncertainty in the metal, and, consequently, to discard its use altogether. To some extent, this impression is stiU in existence. To my surprise, only a short time ago quite a promhient engineer told me that he was still using wrought-iron shafts.
The experience with the steel shaft brought the system of hydraulic forging, before alluded to, most vividly to my mind agaui, but unfortunately Mr. Roberts, who was re¬ ferred to in a foniier chapter, was no more. Consequently I went to the Pencoyd Works, with wliich Mr. Roberts had been connected, but as he had died suddenly the matter had been dropped and I could get no information from them. I then went to see Mr. James Dougherty, the gentleman who went with Mr. Roberts to Vienna, but could get no