The next question was that of the lock on the cell-bars. The closest inspection he could give did not reveal the joints; they were extraordinarily well fitted. On the other hand, he remembered that the arm of the truck had reached under one of the lower bars. Lying flat on his back, Sherman pulled himself along from bar to bar, inspecting each in turn. About mid-way along the front of the cell, he perceived a tiny orifice in the base of one bar--a mere pin-hole. Marvelling at the delicacy of the adjustment which could use so tiny a hole as a lock he sat down to consider the question. He was completely naked and had nothing but the objects that had been placed in his cell by his jailers. However-- Among the assortment of tools in his bureau was a curve-bladed knife with the handle set parallel to the blade as though it were meant for chopping, and forming the wall of the same drawer was a strip of a material like emery cloth. After some experimenting he found a finger-hole which, when squeezed, caused this emery-cloth to revolve, giving a satisfactory abrasive. Thus armed with a tool and a means of keeping an edge on it, he took one of the metal bands from the drawer that contained the duplicate set of hands and set to work on it.... Producing a needle that would penetrate the hole in the bars was all of three days' work, though he had no means of marking the time accurately. The metal band was pliable, light, and for all its pliability and lightness, incredibly hard. His tool would barely scratch it and required constant sharpenings. Moreover, he had little time to himself; his unseen scholar required constant lessons in English. But at last the task was done. Choosing a moment when one of the cages at his side was empty and the occupant of the other was busy over some silly sport of his own--tossing a ball from one hand to another--Sherman lay down on the floor, found the opening and drove his needle home. Nothing happened. He surveyed the result with disappointment. It was disheartening, after so much labor to attain no result at all. But it occurred to him that perhaps he had not learned the whole secret of the arm, and the next time the car came down the corridor for him, he was lying on the floor, carefully watching the opening. As he had originally surmised, a needle-like point was driven home. But he noted that on either side of the point the arm gripped the bar tightly, pressing it upward. This presented another difficulty. He had only two hands; if one of them worked the needle he could grip the bar in only one place. But he remembered, fortunately, that his toes had showed a remarkable power of prehension since the change that had made him into a machine.