Oak sole leather, the foreman said, was often considered preferable for soling shoes because its close fibre rendered it waterproof, and it seldom cracked. Much of the fine English leather imported into this country was, Peter learned, oak tanned. Since oaks grew so plentifully in Great Britain the bark was much less expensive there than here. Hemlock leather--so deep red in color--was, on the other hand, used largely for heavy, stiff soles to common shoes for men and boys, since it made up in wear what it lacked in flexibility. Union leather, being a combination of both oak and hemlock tannage, possessed the virtues as well as the faults of each; it had not the deep red of hemlock, nor the fine fibre of oak tanned leather. Still it was a flexible material and was used, the foreman told Peter, for soling women's shoes. Sole leather seemed to the boys a very stiff and solid stuff after the calf and sheep skins which they had previously handled. Perhaps they did not enjoy the Elmwood tanneries quite as much as the home works at Milburn, and perhaps they longed a little for their term of service there to be completed. Nevertheless they made friends, learned much that they were anxious to know, and had their motor rides over and back each day together. With so many of his ambitions reaching fulfilment it began to seem to Peter as if life were a very smooth sea, and it was not until June when he and Nat were transferred to the patent leather factory that he had his first experience in navigating rough waters. This storminess came about through Tolman, a sharp-tongued foreman who did not hesitate to announce that too much favoritism had been shown Peter Strong in the past. "I bet if he ever comes to the patent leather factory and I get the chance I will take some of the starch out of him," Tolman had been heard to declare. Unluckily he held just enough authority to be able to carry out his threat. Power had hitherto been to him an unknown weapon. He had been given the position of acting foreman of the new patent leather factory only because of his long term of service with the company. It was understood that he was to hold the post until a skilled and competent foreman could be found; but while he enjoyed the distinction of "boss" he made as arrogant use of his sovereignty as he could.