As he is going he blames me out-right. "I can make excuses for the child," he says, "he sinned in ignorance. But you, sir, should know better. Why did you let him do it? As you are living together and you are older than he, you should look after him and give him good advice. Your experience should be his guide. When he is grown up he will reproach, not only himself, but you, for the faults of his youth." When he is gone we are greatly downcast. I blame myself for my easy-going ways. I promise the child that another time I will put his interests first and warn him against faults before he falls into them, for the time is coming when our relations will be changed, when the severity of the master must give way to the friendliness of the comrade; this change must come gradually, you must look ahead, and very far ahead. We go to the fair again the next day to see the trick whose secret we know. We approach our Socrates, the conjuror, with profound respect, we scarcely dare to look him in the face. He overwhelms us with politeness, gives us the best places, and heaps coals of fire on our heads. He goes through his performance as usual, but he lingers affectionately over the duck, and often glances proudly in our direction. We are in the secret, but we do not tell. If my pupil did but open his mouth he would be worthy of death. There is more meaning than you suspect in this detailed illustration. How many lessons in one! How mortifying are the results of a first impulse towards vanity! Young tutor, watch this first impulse carefully. If you can use it to bring about shame and disgrace, you may be sure it will not recur for many a day. What a fuss you will say. Just so; and all to provide a compass which will enable us to dispense with a meridian! Having learnt that a magnet acts through other bodies, our next business is to construct a bit of apparatus similar to that shown us. A bare table, a shallow bowl placed on it and filled with water, a duck rather better finished than the first, and so on. We often watch the thing and at last we notice that the duck, when at rest, always turns the same way. We follow up this observation; we examine the direction, we find that it is from south to north. Enough! we have found our compass or its equivalent; the study of physics is begun.