In a few hours I was back in Philadelphia, and the next few evenings I made my headquarters at Peter Burns’s house. For the time being I became the professor, and Billy, the day watchman, the pupil. He was very apt, I must confess,--far ahead of John Taylor in the Ocean Bank job, though the latter was most satisfactory under instructions. I put Billy through the same course of study to which Taylor had been subjected. I told him of the part Taylor played in the Ocean Bank job and the profit that came to him through its success. In an exceedingly short time I had the day watchman well taught and almost to the bursting point with enthusiasm. Having him so well in hand, I instructed him to try his luck on the vault lock. It wouldn’t surprise me, I told him, if he wasted many hours before attaining success. It was agreed that I wait near his house in Spring Garden Street, each evening, in quest of his report. Accordingly I was on hand. Several times I met the lad, only to know by his face, before he could tell me, that he was meeting with disappointment. It was, perhaps, the tenth evening after I had given him his first lesson on locks that I was in the vicinity of his house, anxiously waiting for him. Presently I saw him coming, a considerable distance away. The street lamps shed none too much light, yet I could divine, from his general manner, that he had good news. When he drew near so that I could see his face, it was lit up with the fire of success. I knew it right away. He was excited to the limit. “I’ve got it, for sure. I’ve got it,” he exclaimed. His enthusiasm would not have been inappropriate in a better cause. I hadn’t time to ask him how it was accomplished, when he continued:-- “When they unlocked the vault this morning, I felt certain that I’d got my eye on the right combination numbers.” “And you’d like to have tried the door right away?” I asked, and my eyes twinkled with mischief. “My Lord!” he exclaimed, “it seemed I couldn’t wait till they all got out. I wasn’t fit for my regular work the rest of the day.” “Well, the clerks went away, and you--” “When they’d all gone,” interrupted Billy, “I tried my numbers, and they opened the lock the very first time.” “How do you know you unlocked the vault door?” I inquired, half seriously and half teasingly. “I proved it,” he whispered in my ear; “I proved it. I threw back the bolts and opened the door. Isn’t that proof enough?” I admitted it was. Billy went on: “This getting combinations to safes is dead easy. If I could only be inside the vault when the tellers unlock their safes, without attracting attention, we could soon put the Corn Exchange Bank out of business.” Now, surely here was an enthusiastic bank employee with his enthusiasm misdirected. I saw right away that I must cool him off if I was to depend upon him for a level head in an emergency. Brains and coolness, in my business, were the corner-stones of success.