The same principle is at the basis of all efficient pedagogy.  The competent teacher endeavors by some association of ideas to link every new fact with those facts which the pupil already has acquired.

In the pursuit of this method the teacher will “compare all that is far off and foreign to something that is near home, making the unknown plain by the example of the known, and connecting all the instruction with the personal experience of the pupil—­if the teacher is to explain the distance of the sun from the earth, let him ask, ’If anyone there in the sun fired off a cannon straight at you, what should you do?’ ’Get out of the way,’ would be the answer.  ‘No need of that,’ the teacher might reply; ’you may quietly go to sleep in your room and get up again; you may wait till your confirmation day, you may learn a trade, and grow as old as I am—­then only will the cannon-ball be getting near, then you may jump to one side!  See, so great as that is the sun’s distance!’”

We shall now show you how to apply this principle in improving your memory and in making a more complete use of your really vast store of knowledge.

Rule I. Make systematic use of your sense-organs.

[Sidenote:  How to Remember Names]

Do you find it difficult to remember names?  It is because you do not link them in your mind with enough associations.  Every time a man is introduced to you, look about you.  Who is present?  Take note of as many and as great a variety of surrounding facts and circumstances as possible.  Think of the man’s name, and take another look at his face, his dress, his physique.  Think of his name, and at the same time his voice and manner.  Think of his name, and mark the place where you are now for the first time meeting him.  Think of his name in conjunction with the name and personality of the friend who presented him.

Memory is not a distinct faculty of mind in the sense that one man is generously endowed in that respect while another is deficient.  Memory, as meaning the power of voluntary recall, is wholly a question of trained habits of mental operation.

Your memory is just as good as mine or any other man’s.  It is your indifference to what you would call “irrelevant facts” that is at fault.  Therefore, cultivate habits of observation.  Fortify the observed facts you wish to recall with a multitude of outside associations.  Never rest with a mere halfway knowledge of things.

[Sidenote:  Five Exercises for Developing Observation]

To assist you in training yourself in those habits of observation that make a good memory of outside facts, we append the following exercises: 

a. Walk slowly through a room with which you are not familiar.  Then make a list of all the contents of the room you can recall.  Do this every day for a week, using a different room each time.  Do it not half-heartedly, but as if your life depended on your ability to remember.  At the end of the week you will be surprised at the improvement you have made.