THERE is a safety gate in each lock, to protect, in case of accident, the main lock gate, just suggested, with the figures working at the armor-plate facing, on the extreme right. Beyond are the outer walls and approaches of the upper lock, and beyond these, but unseen, the lake. At the bottom is the railroad and the temporary opening shown in the previous drawing. The scale, the immensity of the whole may be judged by the size of the engines and figures. I have never seen such a magnificent arrangement of line, light and mass, and yet those were the last things the engineers thought of. But great work is great art, and always was and will be. This is the Wonder of Work.