The Essential Writings of Jean-Jacques Rousseau. Jean-Jacques Rousseau

many vain attempts accompanied by derisive shouts from the audience the child complains that he is being cheated, that is not the same duck, and he defies the conjuror to attract it.

      The conjuror, without further words, takes a bit of bread and offers it to the duck, which at once follows it and comes to the hand which holds it. The child takes the same bit of bread with no better success; the duck mocks his efforts and swims round the basin. Overwhelmed with confusion he abandons the attempt, ashamed to face the crowd any longer. Then the conjuror takes the bit of bread the child brought with him and uses it as successfully as his own. He takes out the bit of iron before the audience—another laugh at our expense—then with this same bread he attracts the duck as before. He repeats the experiment with a piece of bread cut by a third person in full view of the audience. He does it with his glove, with his finger-tip. Finally he goes into the middle of the room and in the emphatic tones used by such persons he declares that his duck will obey his voice as readily as his hand; he speaks and the duck obeys; he bids him go to the right and he goes, to come back again and he comes. The movement is as ready as the command. The growing applause completes our discomfiture. We slip away unnoticed and shut ourselves up in our room, without relating our successes to everybody as we had expected.

      Next day there is a knock at the door. When I open it there is the conjuror, who makes a modest complaint with regard to our conduct. What had he done that we should try to discredit his tricks and deprive him of his livelihood? What is there so wonderful in attracting a duck that we should purchase this honour at the price of an honest man's living? "My word, gentlemen! had I any other trade by which I could earn a living I would not pride myself on this. You may well believe that a man who has spent his life at this miserable trade knows more about it than you who only give your spare time to it. If I did not show you my best tricks at first, it was because one must not be so foolish as to display all one knows at once. I always take care to keep my best tricks for emergencies; and I have plenty more to prevent young folks from meddling. However, I have come, gentlemen, in all kindness, to show you the trick that gave you so much trouble; I only beg you not to use it to my hurt, and to be more discreet in future." He then shows us his apparatus, and to our great surprise we find it is merely a strong magnet in the hand of a boy concealed under the table. The man puts up his things, and after we have offered our thanks and apologies, we try to give him something. He refuses it. "No, gentlemen," says he, "I owe you no gratitude and I will not accept your gift. I leave you in my debt in spite of all, and that is my only revenge. Generosity may be found among all sorts of people, and I earn my pay by doing my tricks not by teaching them."

      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.

      There are various regions of the earth, and these regions differ in temperature. The variation is more evident as we approach the poles; all bodies expand with heat and contract with cold; this is best measured in liquids and best of all in spirits; hence the thermometer. The wind strikes the face, then the air is a body, a fluid; we feel it though we cannot see it. I invert a glass in water; the water will not fill it unless you leave a passage for the escape of the air; so air is capable of resistance. Plunge the glass further in the water; the water will encroach on the air-space without filling it entirely; so air yields somewhat to pressure. A ball filled with compressed air bounces better than one filled with anything else; so air is elastic. Raise your arm horizontally from the water when you are lying in your bath; you will feel a terrible weight on it; so air is a heavy body. By establishing an equilibrium between air and other fluids its weight can be measured, hence the barometer, the siphon, the air-gun, and the air-pump. All the laws of statics and hydrostatics are discovered by such rough experiments. For none of these would I take the child into a physical cabinet; I dislike that array of instruments and apparatus. The scientific atmosphere destroys science. Either the child is frightened by these instruments or his attention, which should be fixed on their effects, is distracted by their appearance.

      We shall make all our apparatus ourselves, and I would not make it beforehand, but having caught a glimpse of the experiment by chance we mean to invent step by step an instrument for its verification. I would rather our apparatus was somewhat clumsy and imperfect, but our ideas clear as to what the apparatus ought to be, and the results to be obtained by means of it. For my first lesson in statics, instead of fetching a balance, I lay a stick across the back of a chair, I measure the two parts when it is balanced; add equal or unequal weights to either end; by pulling or pushing it as required, I find at last that equilibrium is the result of a reciprocal proportion between the amount of the weights and the length of the levers. Thus my little physicist is ready to rectify a balance before ever he sees one.

      Undoubtedly the notions of things thus acquired for oneself are clearer and much more convincing than those acquired from the teaching of others; and not only is our reason not accustomed to a slavish submission to authority, but we develop greater ingenuity in discovering relations, connecting ideas and inventing apparatus, than when we merely accept what is given us and allow our minds to be enfeebled by indifference, like the body of a man whose servants always wait on him, dress him and put on his shoes, whose horse carries him, till he loses the use of his limbs. Boileau used to boast that he had taught Racine the art of rhyming with difficulty. Among the many short cuts to science, we badly need some one to teach us the art of learning with difficulty.

      The most obvious advantage of these slow and laborious inquiries is this: the scholar, while engaged in speculative studies, is actively using his body, gaining suppleness of limb, and training his hands to labour so that he will be able to make them useful when he is a man. Too much apparatus, designed to guide us in our experiments and to supplement the exactness of our senses, makes us neglect to use those senses. The theodolite makes it unnecessary to estimate the size of angles; the eye which used to judge distances with much precision, trusts to the chain for its measurements; the steel yard dispenses with the need of judging weight by the hand as I used to do. The more ingenious our apparatus, the coarser and more unskilful are our senses. We surround ourselves with tools and fail to use those with which nature has provided every one of us.

      But when we devote to the making of these instruments the skill which did instead of them, when for their construction we use the intelligence which enabled us to dispense with them, this is gain not loss, we add art to nature, we gain ingenuity without loss