A survey of the premises satisfied the gang that, massive though it appeared, with its ponderous iron walls and complicated locks, the vault of this bank was by no means impossible of access. The floor above the bank was occupied by the Young Men's Christian Association, one of the association's rooms being directly over the vault. There was the floor between, and under that four feet of solid masonry, some of the stones in it weighing a ton. And under the masonry was a layer of railroad iron, resting on a plate of hardened steel an inch and a half thick. All this, however, so far from discouraging the conspirators, gave them greater confidence in the success of their plan, once under way, since the very security of the vault, by structure, from overhead attack lessened the strictness of the surveillance. Indeed, the most serious difficulty, in the estimation of the robbers, was to gain easy and unsuspected admission to the quarters of the Young Men's Christian Association, on the second floor. The secretary, a very prudent man, had put on the outside door of the association rooms an improved Yale lock, which was then new upon the market and offered unusual obstacles to the lock-picker. Neither Dunlap, Scott, nor any of their associates had skill enough to open this lock without breaking it, which would, of course, have been fatal to their plan. For days, therefore, after all the other details of the robbery had been arranged, the whole scheme seemed to be blocked by a troublesome lock on an ordinary wooden door. So serious a matter did this finally become that Scott and Dunlap went to the length of breaking into the secretary's house at night, and searching his pockets, in the hope of finding the keys and getting an impression of them. But here, again, the secretary had taken precautions that defeated their purpose, for he had hidden the keys under a carpet, where the robbers never thought of looking for them. Disappointed in their search, they went away, making no attempt to carry off anything, a bit of forbearance which caused the excellent secretary much wonder the next morning, when he found that nothing was missing, although there were plain traces of intruders. The Yale lock still continuing an insoluble difficulty, Perry finally made a journey to New York, in the hope of finding some device by which to open it. There, in the course of his search, and in a curious way, he made the acquaintance of Evans, then a salesman in the employ of a prominent safe-company.