SIR ISAAC NEWTON,
It is so well known, as scarcely to need repeating here, displayed his wondrous and incontrollable tendency for scientific inquiry in boyhood. In him, too, as in the minds of almost all philosophical discoverers, was evinced the faculty for mechanical contrivance, as well as acuteness for demonstration. The anecdotes of his boyish invention, of his windmill with a mouse for the miller, his water-clock, carriage, and sun-dials, and of his kites and paper lanterns, are familiar. His mother having been persuaded, by an intelligent relative, to give him up from agricultural cares, to which his genius could not be tied down, he was sent to Cambridge, and entered Trinity College in his eighteenth year. He proceeded, at once, to the study of “Descartes’ Geometry,” regarding “Euclid’s Elements” as containing self-evident truths, when he had gone through the titles of the propositions. Yet he afterwards regretted this neglect of the rigid method of demonstration, in the outset, as a great mistake, and wished he had not attached himself so closely to modes of solution by algebra. He successively studied, and wrote commentaries on, “Wallis’s Arithmetic of Infinities,” “Saunderson’s Logic,” and “Kepler’s Optics;” and, for testing the doctrines of the latter science, bought a prism, and made numerous experiments with it. While but a very young man, Dr. Isaac Barrow, the Lucasian Professor of Mathematics, gathered hints of new truths from his conversation; and in the publication of his lectures on optics, a few years after, the Doctor acknowledged his obligations to young Newton, and characterised him very highly. A year after this publication, Barrow resigned his chair in favour of Newton, who had recently taken the degree of Master of Arts.
Zeal to acquit himself well in his professorship, a situation so congenial to his mind, led him to devote the most profound attention to the doctrines of light and vision. Realities were what he sought, even in the most abstract pursuits; and he expended considerable manual labour in constructing reflecting telescopes. One of these most valued relics of his mechanical toil is now in the library of the Royal Society. The result of his studies and experiments was not fully known before the publication of his “Opticks,” in his sixty-second year; but it is believed his entire discovery of the nature of light was made many years before, being at length “put together out of scattered papers.” The modesty of this great man was, indeed, the most distinguishing mark of his intellect. Arrogant satisfaction, or pride of superior genius, never sullied his greatness. Even in giving this scientific treasure to the world, he says, he designed to repeat most of his observations with more care and exactness, and to make some new ones for determining the manner how the rays of light are bent in their passage by bodies, for making the fringes of colours with the dark lines between them.
How much are we indebted to the patient perseverance of all the true discoverers in science! This is the quality of mind which ever distinguished them. Rashness and presumption, haste to place his crude theories before the world, and to gain assent to them before proof, on the other hand, are the sure marks of the empiric or pretender. The popular author of “The Pursuit of Knowledge under Difficulties”—a work the young student should carry about with him as a never-failing stimulus to perseverance—thus admirably treats this pre-eminent characteristic of the mind of Newton:—“On some occasions he was wont to say, that, if there was any mental habit or endowment in which he excelled the generality of men, it was that of patience in the examination of the facts and phenomena of his subject. This was merely another form of that teachableness which constituted the character of the man. He loved truth, and wooed her with the unwearying ardour of a lover. Other speculators had consulted the book of nature, principally for the purpose of seeking in it the defence of some favourite theory: partially, therefore, and hastily, as one would consult a dictionary. Newton perused it as a volume altogether worthy of being studied for its own sake. Hence proceeded both the patience with which he traced its characters, and the rich and plentiful discoveries with which the search rewarded him. If he afterwards classified and systematised his knowledge like a philosopher, he had first, to use his own language, gathered it like a child.”
This transcendent combination of qualities, modesty, patient investigation, and indefatigable perseverance, was still more wondrously shown in his superlative discovery of the theory of gravitation, than in his promulgation of the laws of light and vision. The anecdote of his observation of the fall of an apple from a tree, while sitting in his garden, is among the most familiar of all anecdotes to general readers. This incident, it was affirmed by his niece, as well as his friend Dr. Pemberton, occurred in Newton’s twenty-third year; and it instantly raised in him the inquiry whether the infinite universe were not held in order and kept in motion by the very power which drew the apple to the earth.
Galileo had already shown the tendency of all bodies near the earth to gravitate towards its centre, and had calculated and fixed the proportions of their speed in descent to their distance from the earth’s centre. Newton’s general application of Galileo’s rule to the planets of the solar system led him to regard his conjecture as strongly probable. He next devoted his powers to the consideration of its verity, by examining the question whether the force of gravitation by which the planets preserved their orbits and motions round the sun would precisely account for the moon’s preservation of her orbit and motion round the earth. But here the precision of his calculations was frustrated by the imperfect knowledge then existing as to the real measurement of the earth—the gravitating centre of the revolving moon. An empiric would have trumpeted his discovery to the world, in spite of the fact that this faulty admeasurement of the earth, by not affording a true calculation of her gravitating power, failed to lead him to an agreement with truth. Newton was silent for long years, until a degree of the earth’s latitude was ascertained, by actual experiment, to be sixty-nine and a half degrees instead of sixty; he then resumed his calculations, and their result was that he had probed the grand secret of the laws by which worlds move in obedience to the suns which are their centres. It only remains to be observed, as a significant reminder to the young reader, that—though he may assent to the great doctrine of Newton, and consider it to be established, he can never fully know its mathematical and mechanical verity, unless study enables him to read the “Principia”—the work in which the truth of gravitation and its laws are demonstrated. Let it be an additional motive to strive for the ability to read such a book, that in having read it the student has become acquainted with the greatest effort in abstract truth ever yet produced by the human intellect.
The moral as well as the intellectual grandeur of the life of Newton would tempt us to enlarge, but we must merely say, ere we pass on, to the youthful inquirer—read about Newton, think about Newton, and the more you know of him the more will your understanding honour him, your heart love him, and your desire strengthen to approach him in virtue, wisdom, and usefulness.