After having fulfilled the duties of secretary with much distinction, but not without some feebleness and negligence in consequence of his bad health, Fourier died the 16th of May, 1830. I declined several times the honor which the Academy appeared willing to do me, in naming me to succeed him. I believed, without false modesty, that I had not the qualities necessary to fill this important place suitably. When thirtynine out of forty-four voters had appointed me, it was quite time that I should give in to an opinion so flattering and so plainly expressed. On the 7th of June, 1830, I, therefore, became perpetual secretary of the Academy for the Mathematical Sciences; but, conformably to the plea of an accumulation of offices, which I had used as an argument to support, in November, 1822, the election of M. Fourier, I declared that I should give in my resignation of the professorship in the Polytechnic School. Neither the solicitations of Marshal Soult, the minister of war, nor those of the most eminent members of the Academy, could avail in persuading me to renounce this resolution. HERSCHEL. BY M. ARAGO. WILLIAM HERSCHEL, one of the greatest astronomers that ever lived in any age or country, was born at Hanover, on the 15th of November, 1738. The name of Herschel has become too illustrious for the world to neglect searching back, along the stream of time, to learn the social position of the families that have borne it. Yet pardonable curiosity on this subject has not been entirely satisfied. We only know that Abraham Herschel, great-grandfather of the astronomer, resided at Mähren, whence he was expelled on account of his strong attachment to the Protestant faith; that Abraham's son Isaac was a farmer in the vicinity of Leipzig; that Isaac's eldest son, Jacob Herschel, disappointed his father's earnest desire to see him devote himself to agriculture, that he determined on being a musician, and settled at Hanover. Jacob Herschel, father of William, the astronomer, was an eminent musician, not less remarkable for the good qualities of his heart than for those of his mind. His very limited means did not enable him to bestow a complete education on his family, consisting of six boys and four girls, although, by his care, his ten children all became excellent musicians. The eldest, Jacob, even acquired a rare degree of skill, which procured for him the appointment of master of the band in a Hanoverian regiment, which he accompanied to England. The third son, William, remained under his father's roof, and, without neglecting the fine arts, took lessons in the French language, and devoted himself to the study of metaphysics, for which he retained a taste to his latest day. In 1759 William Herschel, then about twenty-one years of age, went over to England, not with his father, as has been erroneously stated, but with his brother Jacob, whose connections in that country seemed likely to favor the young man's opening prospects in life. But neither London nor the country towns afforded him any resource in the beginning, and the first two or three years after his expatriation were marked with cruel privations, which were, however, manfully endured. A fortunate chance finally raised the young Hanoverian to a better position; Lord Durham engaged him as master of the band in an English regiment which was quartered on the borders of Scotland. From this moment he began to acquire a reputation as a musician that was gradually extended, until in 1766 he was appointed organist at Halifax, (Yorkshire.) The emoluments of this situation, together with those of giving private lessons both in the town and the country around, afforded him the means to remedy, or rather to complete, his early education. It was then that he learned Latin and Italian, though without any other help than a grammar and a dictionary, and that he also acquired some knowledge of Greek. So great was the desire for knowledge with which he was inspired that while residing at Halifax he found means to continue his philological exercises, and at the same time to study deeply the learned but very obscure mathematical work of Smith on the theory of music. This treatise, either explicitly or implicitly, supposed the reader to have a knowledge of algebra and geometry, which Herschel did not possess, but of which he made himself master in a very short time. In 1766 Herschel obtained the appointment of organist to the Octagon Chapel at Bath. This was a more lucrative post than that at Halifax, but it also devolved on him new obligations. He had to play incessantly either at the oratorios, or in the rooms at the baths, at the theater, and in the public concerts. Besides this, from among his patrons in the most fashionable circle of England, he could not refuse to take numerous pupils who wished to be instructed in his art. It is difficult to imagine how, among so many duties, so many distractions of various kinds, Herschel could continue the studies, which even at Halifax had required so much resolution and perseverance, with a very uncommon degree of talent. We have seen that it was by music that Herschel was led to mathematics; mathematics in their turn led him to optics, the principal and fertile source of his illustrious career. The time finally arrived when his theoretic knowledge was to guide the young musician into a laborious application of principles quite foreign to his habits; and of which the brilliant success, as well as the excessive temerity, must excite reasonable astonishment. A telescope-a simple reflector, only. two English feet in length falls into the hands of Herschel during his residence at Bath. This instrument, however imperfect, shows him a multitude of stars in the sky that the naked eye cannot discern; shows him also enlarged known objects, under their true dimensions; reveals forms to him that the richest imaginations of antiquity had never suspected. He is transported with enthusiasm, and resolves, without delay, to have a similar instrument but of larger size. The answer from London is delayed for some days. These few days appear to him as years. When the answer arrives, the price that the optician demands proves to be much beyond the pecuniary resources of a mere organist. To any other man this would have been an unsurmountable obstacle. This unexpected difficulty, on the contrary, inspired Herschel with fresh energy. He cannot buy a telescope; then he will construct one with his own hands. The musician of the Octagon Chapel rushes immediately into a multitude of experiments, on metallic alloys that reflect light with the greatest intensity, on the means of giving the parabolic figure to the mirrors, on the causes that in the operation of polishing affect the regularity of the reflection, &c. So rare a degree of perseverance at last receives its reward. In 1774 Herschel has the happiness of being 199 able to examine the heavens with a Newtonian telescope of five English feet focus, entirely made by himself. This success tempts him to undertake still more difficult enterprises. Other telescopes of seven, of eight, of ten, and even of twenty feet focal distance, crown his efforts. As if to answer in advance those critics who would have accused him of a superfluity of apparatus, of unnecessary luxury, in the large size of the new instruments, and his extreme minutia in their execution, Nature granted to the astronomical musician, on the 13th of March, 1781, the unprecedented honor of commencing his career of observation with the discovery of a new planet, situated on the confines of our solar system. Dating from that moment, Herschel's reputation, no longer in his character of musician, but as a constructor of telescopes and as an astronomer, spread throughout the world. George III, a lover of science, and much inclined besides to protect and patronize both men and things of Hanoverian origin, had Herschel presented to him. He was charmed with the simple yet lucid and modest account that the astronomer gave of his repeated endeavors; he caught a glimpse of the glory that such an observer might reflect on his reign; granted him a pension of three hundred guineas a year, and furnished him with a residence near Windsor Castle, first at Clay Hall and then at Slough. The anticipations of George III were completely realized. We may confidently assert, relative to the little house at Slough, that it is the place of all the world where the greatest number of astronomical discoveries have been made. The name of that village will never perish. Science will transmit it religiously to our latest posterity. I shall avail myself of this opportunity to rectify a mistake, of which ignorance and idleness wish to make a triumphant handle, or, at all events, to wield in their cause as an irresistible justification. It has been repeated to satiety that at the time when Herschel entered on his astronomical career he knew nothing of mathematics. But I have already said that, during his residence at Bath, the organist of the Octagon Chapel had familiarized himself with the principles of geometry and algebra; and a still more positive proof of this is, that a difficult question on the vibration of strings loaded with small weights having been proposed for discussion in 1779, Herschel gave it a solution which was thought worthy to be inserted in several scientific periodicals of the year 1780. The adventurous life of Herschel is here closed. The great astronomer will not quit his observatory any more, except to submit the sublime results of his laborious vigils to the Royal Society of London. These results are contained in his memoirs; they constitute one of the principal riches of the celebrated collection known under the title of Philosophical Transactions. Herschel was even elected as a member of the principal academies of Europe, and about 1816 he was named a Knight of the Guelphic Order of Hanover. According to the English custom, from the time of that nomination the title of Sir William took the place, on all his memoirs, already honored with so much celebrity, of the former appellation of Doctor William. He had been named a doctor of laws in the University of Oxford in 1786. This dignity, by special favor, was conferred on him without any of the obligatory formalities of examination, disputation, or pecuniary contribution, usual in that learned corporation. I should wound the elevated sentiments that Herschel professed all his life, if I were not here to mention two indefatigable assistants that this fortunate astronomer found in his own family. The one was Alexander Herschel, endowed with a remarkable talent for mechanism, always at his brother's service, and who enabled him to realize without delay any ideas that he had conceived; the other was Miss Caroline Herschel, who deserves a still more particular and detailed mention. * Miss Caroline Lucretia Herschel went to England as soon as her brother became special astronomer to the King. She received the appellation there of Assistant Astronomer, with a moderate salary. From that moment she unreservedly devoted herself to the service of her brother, happy in contributing night and day to his rapidly increasing scientific reputation. Miss Caroline shared in all the night-watches of her brother, with her eye constantly on the clock, and the pencil in her hand; she, without exception, recorded all the observations; she afterward made three or four copies in separate registers; coördinated, classed, and analyzed them. If the scientific world saw with astonishment how Herschel's works succeeded each other with unexampled rapidity during so many years, they were specially indebted for it to the ardor of Miss Caroline. Astronomy, moreover, has been directly enriched with several comets by this excellent and respectable lady. After the death of her illustrious brother, she retired to Hanover, to the house of Jahn Dietrich Herschel, a musician of high reputation, and the only surviving brother of the astronomer. William Herschel died without pain on the 23d of August, 1822, aged eighty-three. Neither fame nor fortune ever changed in him the fund of infantine candor, inexhaustible benevolence, and sweetness of character with which nature had endowed him. He preserved to the last both his brightness of mind and vigor of intellect. For some years before his death he enjoyed with delight the distinguished success of his only son, Sir John Herschel. At his last hour he sunk to rest with the pleasing conviction that his beloved son, heir of a great name, would not allow it to fall into oblivion, but would adorn it with fresh luster, * When age and infirmities obliged Alexander Herschel to give up his profession as a musician, he quitted Bath and returned to Hanover, very generously provided by Sir William with a comfortable independence for life. + Sir W. Herschel had married Mary, the widow of John Pitt, esq., possessed of a considerable jointure, and the union proved a remarkable accession of domestic happiness. This lady survived Sir William by several years. They had but this son.-TRANSLATOR'S NOTE. |