There must be an interval of rest for the nerve before the sensation can be renewed in its first freshness. Now it is the same, though in a less degree, with the more important sense of sight. We look long and steadily at a thing to know it, and the longer and more fixedly we look the better, if it engages the reasoning faculties; but an aesthetic pleasure cannot be increased or retained in that way. We must look, merely glancing as it were, and look again, and then again, with intervals, receiving the image in the brain even as we receive the "nimble emanation" of a flower, and the image is all the brighter for coming intermittently. In a large prospect we are not conscious of this limitation because of the wideness of the field and the number and variety of objects or points of interest in it; the vision roams hither and thither over it and receives a continuous stream or series of pleasing impressions; but to gaze fixedly at the most beautiful object in nature or art does but diminish the pleasure. Practically it ceases to be beautiful and only recovers the first effect after we have given the mind an interval of rest. Strolling about the green with this thought in my mind, I began to pay attention to the movements of a man who was manifestly there with the same object as myself--to look at the cathedral. I had seen him there for quite half an hour, and now began to be amused at the emphatic manner in which he displayed his interest in the building. He walked up and down the entire length and would then back away a distance of a hundred yards from the walls and stare up at the spire, then slowly approach, still gazing up, until coming to a stop when quite near the wall he would remain with his eyes still fixed aloft, the back of his head almost resting on his back between his shoulders. His hat somehow kept on his head, but his attitude reminded me of a saying of the Arabs who, to give an idea of the height of a great rock or other tall object, say that to look up at it causes your turban to fall off. The Americans, when they were chewers of tobacco, had a different expression; they said that to look up at so tall a thing caused the tobacco juice to run down your throat.