The mind differs from the wave of water in that it is not extensive to the right and left of its course. It is like a hill with a small crest that can bold but few objects upon its surface. When we say we are thinking profoundly upon a subject we mean that the subject and its connections are continuously upon the crest of the wave, and that unrelated things are either not in the mind at all or they are at least not at the focus.

The things that are in the mind but not focal are continually striving, as if they were alive and very active to get at the focal point. Just as the eye is continually tempted to wander, making one object after another its focal one, so the mind is bound to travel unless it has been trained to turn from the thing to its relations and related things and from them back to the main thing again. That is the only way to pay attention. You cannot pay attention to one physical thing for more than an instant. But you can bold a chain of connected things running through the mind, but the things are continually modified by their relations and the absolutely same thing is never again in the mind. When it appears again it is clothed upon or enlarged or modified by what the mind has discovered about it and its relations or has invented and attached to it.

It is easy to repeat the multiplication table without having it focal in the mind. You may read half a page of print with your focal point upon some other matter. You may pray and find in your mind at the same moment a wicked thought. Worse than this, you may continue your prayer and the wicked thought may become focal. Not by your desire that it shall be so, but by the power of marginal things in the mind which makes them focal without your apparent anticipation or desire to have them at the focus. You cannot say that the multiplication table is not in the mind when you are repeating it and wondering who will be at the party this evening. It is there but not focal. When you are reading the words of the page the words may be in your mind, but the focal point may be occupied at the time by wondering how the baby learned to climb so young and guessing whether you ought to catch her or run the risk of her falling, and if she should fall how much she would be injured, what the people would think of you for sitting there and letting her fall, why babies have to fall so much, whether they really learn much about slipping or center of gravity by falls so early in life, and a thousand other items in child study. But the reading is in your mind much as it used to be when your teacher said to you, "Now I want to see you keep your eyes on your book for fifteen minutes without looking off."

The mind grows at first by use of the senses. The sight is the main instrument of youthful mental growth. Things which can be seen or visually remembered are most appropriate subjects for juvenile thinking. You cannot well converse with children upon the pleasures of hope, the uses of adversity, nor any of the forms of mind stuff that are called abstractions. True, they like to play upon words and commit them to memory so as to reproduce them. But this is not because of the real meaning of the words committed but because the ear is pleased. Children enjoy talking like adults as well as looking and acting like them in their unstudied masquerades.

The proper material for juvenile mind action is what may be acquired by the senses. All those subjects in the second paragraph of this article are mainly appeals to the senses. These readily become focal in any mind, but chiefly in the mind that has never been trained away from the senses by abstract thinking. No child can pay attention to anything else when a bird flies in at the window. The bird and its act, its motive, its fellows, its appearance, its nest, its young, and a thousand other notions rush to the focus of his mind, no matter how diligently he may strive to keep them down. Instead of repressing in the mind what is naturally inclined to become focal, education is now finding out the value of permitting these things to come naturally into the mind and so operating upon them that mental growth ensues with little or no friction, and without asking the learner to flag gellate himself continually that he may have knowledge to use in that distant and half-believed — in time when he shall be a man.

Everyone knows that children are delighted with colored pictures. But there is an intensity of delight aroused by a certain class of colored pictures which has been a matter of surprise to most educators and parents since color photography has become practical for illustration. Infants in arms, who have never seen any birds except a few of the size of a canary, are so fascinated with the bird charts that psychologists have found a new problem presented.

If we look upon the child as he views an accurate colored picture we note that be is affected just the same as if the bird itself were before him. His imagination carries him beyond the picture to the thing itself, even in the instances where he has never seen the bird nor any like it. As to his mental state, we can say that the bird rises directly to the focal point in his mind, and it is not the bird picture that holds him, but the bird itself. For teaching purposes this is peculiarly fortunate, for the child is ready to grasp any suggestion from the teacher in order to enjoy the bird more at length. All the subjects of school work will ordinarily appeal to the child, rising readily into the focus of attention where the bird, its relations, its acts, and things pertaining to it, become the material for school activity.