Sir Isaac Newton was born at Woolstrope, in Lincoln, December 25, 1642; after due preparation he was admitted in the University of Cambridge. The rapidity of his progress in mathematical knowledge was truly astonishing. At the age of twenty-four, he had laid the foundation of the most important mathematical discoveries. He is the first who gave a rational and complete account of the laws which regulate planetary motion, on the principles of attraction and gravitation. Newton was as remarkable for a modest diffidence of his own abilities, as for the superiority of his genius. In 1704, he published his “Optics;” in 1711, his “Fluxions;” and in 1728, his “Chronology.” He received in his life time the honour due to his singular merit. In 1703, he was elected President of the Royal Society. In 1705, he received the honour of knighthood by Queen Anne.—He was twice member of parliament. In 1669, he was made master of the mint, which, with the presidency of the Royal Society, he held till his death, in 1726. He was buried in Westminster Abbey, where there is an appropriate monument to his memory.
The system of Newton had an eminent supporter and able annotator in the very eminent Scottish professor, Colin Mac Laurin, who was born in the month of February, 1698. In 1719, he travelled to London, where he was introduced to the illustrious Newton, whose notice and friendship he obtained, and ever after reckoned as the greatest honour and happiness of his life. In 1734, Dr. Berkeley, Bishop of Cloyne, published his treatise, called “The Analyst,” in which he attempted to charge mathematicians with infidelity in matters of religion. This work was the occasion of Mac Laurin’s elaborate “Treatise on Fluxions,” published at Edinburgh, in 1742, which is reckoned the most ample treatise on that branch of novel mathematics which has yet appeared. So very eminent was Mac Laurin’s skill in mathematics, and the principles of anatomical science, and he possessed such excellent instruments for these purposes, that a new theory never appeared, nor did anything transpire in the scientific world, which was uncommon, but his friends constantly resorted to him for explanation and experiment, and their laudable curiosity was sure to be satisfactorily gratified.
One of the greatest names in the modern history of astronomical discovery is that of the late Sir William Herschel; and, much to his praise, he was self-instructed in the science in which he earned his high reputation. Herschel was born at Hanover, in 1736, and was the son of a musician in humble circumstances. Brought up to his father’s profession, at the age of fourteen he was placed in the band of the Hanoverian Guards. A detachment of this regiment having been ordered to England in the year 1757, he and his father accompanied it; but the latter returned to Germany in a few months, and left his son to try his fortune in London. For a long time he had many difficulties to contend with, and he passed several years principally in giving lessons in music in the different towns in the North of England. At last, in 1765, through the interest of a gentleman to whom his merits had become known, he obtained the situation of organist at Halifax; and next year, having gone to fulfil a short engagement at Bath, he gave so much satisfaction by his performances, that he was appointed to the same office in the Octagon Chapel of that city, upon which he went to reside there. The place which he now held was of some value; and from the opportunities which he enjoyed of adding to its emoluments, by engagements at the rooms and private concerts, as well as by taking pupils, he had had the prospect of deriving a good income from his profession, if he had made that his only or his chief object.
During his residence at Bath, although greatly occupied with professional engagements, the time he devoted to his mathematical studies was surprising. Often, we are told, after a fatiguing day’s work of fourteen or sixteen hours among his pupils, he would, on returning home at night, repair for relaxation to what many would deem these severer exercises. In this manner, in the course of time, he attained a competent knowledge of geometry, and found himself in a condition to proceed to the study of the different branches of physical science which depend upon the mathematics. Among the first of the latter that attracted his attention, were the kindred departments of astronomy and optics. Having applied himself to these sciences, he became desirous of beholding with his own eyes those wonders of the heavens of which he had read so much, and for that purpose he borrowed from an acquaintance a two-feet Gregorian telescope. This instrument interested him so greatly, that he determined to procure one of his own, and commissioned a friend in London to purchase one for him, of a somewhat larger size. But he found the price was beyond what he could afford. To make up for this disappointment, he resolved to construct a telescope for himself; and after encountering innumerable difficulties in the progress of his task, he at last succeeded, in the year 1774, in completing a five-feet Newtonian reflector. This was the commencement of a long and brilliant course of triumphs in the same walk of art, and also in that of astronomical discovery. Herschel now became so much more ardently attached to his philosophical pursuits, that, regardless of the sacrifice of emolument he was making, he begun gradually to limit his professional engagements, and the number of his pupils.
Meanwhile he continued to employ his leisure in the fabrication of still more powerful instruments than the one he had first constructed; and in no long time he produced telescopes of seven, ten, and even twenty feet focal distance. In fashioning the mirrors for these instruments, his perseverance was indefatigable. For his seven-feet reflector, we have been informed that he actually finished and made trial of no fewer than two hundred mirrors before he found one that satisfied him. When he sat down to prepare a mirror, his practice was to work at it for twelve or fourteen hours, without quitting his occupation for a moment. He would not even take his hand from what he was about, to help himself to food; and the little he ate on such occasions was put into his mouth by his sister. He gave the mirror a proper shape, more by a certain natural tact than by rule; and when his hand was once in, as the phrase is, he was afraid that the perfection of the finish might be impaired by the least intermission of his labours.
It was on the 13th of March, 1781, that Herschel made the discovery to which he owes, perhaps, most of his reputation. He had been engaged for nearly a year and a half in making a survey of the heavens, when, on the evening of the day that has been mentioned, having turned his reflector (an excellent seven feet reflector of his own constructing) to a particular part of the sky, he observed among the other stars one which seemed to shine with a more steady radiance than those around it; and on account of that and other peculiarities in its appearance, which excited his suspicions, he determined to observe it more narrowly. On reverting to it after some hours, he was a good deal surprised to find that it had perceptibly changed its place—a fact which the next day became more indisputable. At first he was somewhat in doubt whether or not it was the same star which he had seen on these different occasions; but, after continuing his observations for a few days longer, all uncertainty upon that head vanished. He now communicated what he had observed to the astronomer royal, who concluded the luminary could be nothing else than a new comet. Continued observation of it, however, for a few months, dissipated this error; and it became evident that it was in reality a hitherto undiscovered planet. This new world so unexpectedly found to form a part of the system to which our own belongs, received from Herschel, the name of the Georgium Sidus, or Georgian Star, in honour of the King of England; but by continental astronomers it has been more generally called either Herschel, after its discoverer, or Uranus. Subsequent observations, made chiefly by Herschel himself, have ascertained many particulars regarding it, some of which are well calculated to fill us with astonishment at the powers of the sublime science which can wing its way so far into the immensity of space, and bring us back information so precise and various. In the first place, the diameter of this new globe has been found to be nearly four and a half times larger than that of our own. Its size altogether is about eighty times that of our earth. Its year is as long as eighty-three of ours.
Its distance from the sun is nearly eighteen hundred millions of miles, or more than nineteen times that of the earth. Its density, as compared with that of the earth, is nearly as twenty-two to one hundred; so that its entire weight is more than eighteen times that of our planet. Finally the force of gravitation near its surface is such, that falling bodies descend only through fourteen feet during the first second, instead of thirty-two feet as with us. Herschel afterwards discovered no fewer than six satellites, or moons, belonging to his new planet.
The announcement of the discovery of the Georgium Sidus at once made Herschel’s name universally known. In the course of a few months the king bestowed on him a pension of three hundred pounds a year, that he might be able entirely to relinquish his engagements at Bath; and upon this he came to reside at Slough, near Windsor. He now devoted himself entirely to science; and the construction of telescopes, and observations of the heavens, continued to form the occupations of the remainder of his life. Astronomy is indebted to him for many other most interesting discoveries besides the celebrated one of which we have just given an account, as well as a variety of speculations of the most ingenious, original, and profound character. But of these we cannot here attempt any detail. He also introduced some important improvements into the construction of the reflecting telescope—beside continuing to fabricate that instrument of dimensions greatly exceeding any that had been formerly attempted, with the powers surpassing in nearly a corresponding degree, what had ever been before obtained. The largest telescope which he ever made, was his famous one of forty feet long, which he erected at Slough for the king. It was begun about the end of the year 1785, and on the 28th of August, 1789, the enormous tube was poised on the complicated but ingeniously contrived mechanism by which its movements were to be regulated, and ready for use. On the same day a new satellite of Saturn was detected by it, being the sixth which had been observed attendant upon that planet. A seventh was afterwards discovered by means of the same instrument. This telescope has been taken down and replaced by another of only half the length, constructed by Mr. J. Herschel, the distinguished son of the subject of our present sketch. Herschel himself eventually became convinced that no telescope could surpass, in magnifying power, one of from twenty to twenty-five feet in length. The French astronomer, Lalande, states that he was informed by George III. himself, that it was at his desire that Herschel was induced to make the telescope at Slough of the extraordinary length he did, his own wish being that it should not be more than thirty feet long.
So extraordinary was the ardour of this great astronomer in the study of his favourite science, that for many years it has been asserted, he never was in bed at any hour during which the stars were visible. And he made almost all his observations, whatever was the season of the year, not under cover, but in his garden, in the open air—and generally without an attendant. There was much that was peculiar to himself, not only in the process by which he fabricated his telescopes, but also in his manner of using them. One of the attendants in the king’s observatory at Richmond, who had formerly been a workman in Ramsden’s establishment, was forcibly reminded, on seeing Herschel take an observation, of a remark which his old master had made. Having just completed one of his best telescopes, Ramsden, addressing himself to his workman, said, “This, I believe, is the highest degree of perfection we opticians by profession will ever arrive at; if any improvement of importance shall ever after this be introduced in the making of telescopes, it will be by some one who has not been taught by us.”
Some years before his death, the degree of LL.D. was conferred upon Herschel by the University of Oxford; and in 1816, the Prince Regent bestowed upon him the Hanoverian and Guelphic Order of Knighthood. He died on the 23rd of August, 1822, when he was within a few months of having completed his eighty-fourth year.