_Exercise II._ This exercise is but a variation of the first one. It consists in entering a room, and taking a hasty glance around, and then walking out, and afterward writing down the number of things that you have observed, with a description of each. You will be surprised to observe how many things you have missed at first sight, and how you will improve in observation by a little practice. This exercise, also, may be improved by the assistance of a friend, as related in our last exercise. It is astonishing how many details one may observe and remember, after a little practice. It is related of Houdin, the French conjurer, that he improved and developed his faculty of Attention and Memory by playing this game with a young relative. They would pass by a shop window, taking a hasty, attentive glance at its contents. Then they would go around the corner and compare notes. At first they could remember only a few prominent articles--that is, their Attention could grasp only a few. But as they developed by practice, they found that they could observe and remember a vast number of things and objects in the window. And, at last, it is related that Houdin could pass rapidly before any large shop window, bestowing upon it but one hasty glance, and then tell the names of, and closely describe, nearly every object in plain sight in the window. The feat was accomplished by the fact that the cultivated Attention enabled Houdin to fasten upon his mind a vivid mental image of the window and its contents, and then he was able to describe the articles one by one from the picture in his mind. Houdin taught his son to develop Attention by a simple exercise which may be interesting and of value to you. He would lay down a domino before the boy--a five-four, for example. He would require the boy to tell him the combined number at once, without allowing him to stop to count the spots, one by one. "Nine" the boy would answer after a moment's hesitation. Then another domino, a three-four, would be added. "That makes sixteen," cried the boy. Two dominoes at a time was the second day's task. The next day, three was the standard. The next day, four, and so on, until the boy was able to handle twelve dominoes--that is to say, give instantaneously the total number of spots on twelve dominoes, after a single glance. This was Attention, in earnest, and shows what practice will do to develop a faculty. The result was shown by the wonderful powers of observation, memory and attention, together with instantaneous mental action, that the boy developed. Not only was he able to add dominoes instantaneously, but he had powers of observation, etc., that seemed little short of miraculous. And yet it is related that he had poor attention, and deficient memory to begin with.