These characteristics—the lightness with which he held his theories, his vivid imagination, and his philosophical reasoning—are the secrets of Herschel’s success as an astronomer. Nearly all his ideas and speculations have been confirmed. As Arago has said, “We cannot but feel a deep reverence for that powerful genius that has scarcely ever erred.” Herschel, like all other great students of Nature, was deeply religious. He could not observe the heavens without feeling awed at the marvels which his telescopes revealed. In his own words, “It is surely a very laudable thing to receive instruction from the Great Workmaster of Nature.”

Friedrich Wilhelm Herschel, born in Hanover on November 15, 1738, was the fourth child of Isaac Herschel, an oboist in the band of the Hanoverian Guard. Isaac Herschel, a native of Dresden, was an accomplished musician, and all his children, ten in number, inherited his talent. Of these ten, six survived, and only two became famous. These were William, the great astronomer, and his sister Caroline (born on March 16, 1750), who became a student of the heavens only second to her brother.

At the garrison school in Hanover, where the Herschels were educated, William Herschel showed intense love and aptitude for learning, and was more diligent and persevering than his brother Jacob, his senior by four years. In 1753 he became oboist in the band of the Hanoverian Guard in which his father was now bandmaster. In her valuable memoirs, his sister relates that her father was very interested in astronomy, and that he taught his children the names of the constellations. William became devoted to the science, and constructed a small celestial globe on which equator and ecliptic were engraved. But his studies were much hampered. His mother had a great dislike to learning: she had no sympathy with aspirations, and tried to prevent her children becoming well educated. Above all, the Hanoverian Guard was ordered to England in 1755, when a French invasion was feared, and to that country Herschel proceeded, along with his father and brother.

Returning to Germany in 1756, the Hanoverian Guard was employed the following year in the Seven Years’ War. Hanover was invaded by the French, and, conscription being the rule, the musicians were not exempted from service. Under the command of the Duke of Cumberland the Guard suffered a terrible defeat at Hastenbeck. William Herschel spent the night after the battle in a ditch, and decided that soldiering would not be his profession. He deserted, and, with the consent of his parents, he sailed for England. After his arrival at Dover, he wandered through the country in search of musical employment. At length, in 1760, he was appointed to train the band of the Durham Militia, and four years later paid a secret visit to Hanover, where he was welcomed by his father, whose health was now failing, and by his sister Caroline. In the following year he was promoted to the post of organist at Halifax, and in 1766 he removed to Bath as oboist in Linley’s Orchestra. Finally, in 1767, he became organist in the new Octagon Chapel at Bath. Herschel was now twenty-nine years old, and known as a famous musician. As Miss Clerke remarks: “The Octagon Chapel soon became a centre of fashionable attraction, and he soon found himself lifted on the wave of public favour. Pupils of high rank thronged to him, and his lessons often mounted to thirty-five a-week.”

In the year of his appointment his father died, aged sixty, after a life of trouble and hardship. His death was a great blow to his daughter Caroline, whom he had educated when her mother was from home. Caroline Herschel was naturally possessed of musical ability, but her mother and elder brother had determined that she should be a housemaid,—a determination which William, who was devotedly attached to his sister, opposed. Finally, in 1772, he visited Hanover, and took his sister to England with him to act as his housekeeper. But for her unwearied devotion it is doubtful whether William Herschel would have become the great astronomer.

About the time of his appointment in Bath Herschel commenced the study of languages and mathematics, reading Maclaurin’s ‘Fluxions’ and Ferguson’s ‘Astronomy.’ The perusal of the latter volume revived his love for astronomy. After fourteen or sixteen hours’ teaching he would retire to his bedroom and read of the wonders of the heavens. His interest increased as he proceeded, until, in his own words, “I resolved to take nothing upon trust, but to see with my own eyes all that other men had seen before me.” Accordingly he hired a small reflector. Inquiring the price of a larger instrument, he found it to be quite beyond his means. Then in 1772, when his sister came to keep his house for him, he resolved to make his own telescope. First he tried the fitting of lenses into pasteboard tubes, but this being a total failure, he bought the apparatus of a Quaker optician who had constructed, or attempted to construct, reflecting telescopes. In June 1773, assisted by his sister and by his brother Alexander, then in Bath, he commenced work. His first speculum mirror was five inches in diameter; and, while it was in process of construction, he was obliged to hold his hands on it for sixteen hours at a stretch, while his sister supplied his food and read ‘The Arabian Nights,’ ‘Don Quixote,’ and other tales aloud to him to pass the time. At last, after two hundred failures, he finished a 5-inch reflector, and on March 4, 1774, he observed the Orion nebula. No sooner had Herschel commenced his celestial explorations than he resolved to survey the entire heavens, leaving no spot unvisited.

In 1775 he commenced his review of the heavens, but finding his telescope inadequate he began the work of telescope-making afresh. Meanwhile he had much to distract him from astronomy. In 1776 he became director of the Public Concerts at Bath. Yet his enthusiasm was unbounded: he would run to his house between the acts at the theatre to observe the heavens. In 1779, when observing the Moon from the street in front of his house, a gentleman asked permission to see the celestial wonders, a request which Herschel granted. The gentleman, Dr Watson of Bath, introduced Herschel to the Literary Society, and we find him in 1780 contributing two papers to the Royal Society on Mira Ceti and the Moon. In the same year he commenced his second review of the heavens, and during its progress he made his first great discovery. On March 13, 1781, while surveying the constellation Gemini, he discovered a faint object distinguished by a disc, which he concluded to be a tailless comet, but which was soon shown to be a new planet beyond the orbit of Saturn. This was the first planetary discovery made within the memory of man. King George III. summoned Herschel to London, and gave him a pension of £200 a-year, with the title of King’s Astronomer, pardoning him also for his desertion from the army more than twenty years previously. Herschel then named the new planet the “Georgium Sidus,” a title now abandoned and replaced by Uranus.

William and Caroline Herschel now moved to Datchet, near Windsor, in 1785 to Clay Hall, and finally, in 1786, to Slough,—“the spot of all the world,” said Arago, “where the greatest number of discoveries have been made.” Here Herschel and his sister worked for nearly forty years. He communicated to the Royal Society paper after paper on astronomy in all its aspects. He also continued the work of telescope-making, and constructed, in 1789, his 40-foot reflector, the wonder of the age. In 1787 his sister was appointed his assistant, and together the Herschels worked from dusk to dawn. Caroline Herschel herself detected eight comets and numerous nebulÆ. She relates in her memoirs that on one occasion, while she was acting as assistant, the ink froze in her pen. But such inconveniences mattered not to the Herschels. As Miss Clerke has well remarked, “Every serene dark night was to him a precious opportunity, availed of to the last minute. The thermometer might descend below zero, ink might freeze, mirrors might crack; but, provided the stars shone, he and his sister worked on from dusk to dawn.... On one occasion he is said to have worked without intermission at the telescope and the desk for seventy-two hours.”

Honours were showered on Herschel. He was knighted in 1816, and became President of the Royal Astronomical Society in 1820, besides receiving several honorary degrees. But honours in no way elated him. Advancing years in no way affected his wonderful mind. But his duties as King’s Astronomer necessitated his acting as “showman of the heavens” on the visits of royalties to Windsor, often after a whole day’s work, when rest was absolutely necessary. This tremendous strain, which reflects little credit on the Court, proved too much for the old man. His health began to give way, although his mind was as vigorous as ever.

Herschel contributed his last paper to the Royal Society in 1818, and three years later sent a list of double stars to the new Astronomical Society. He made his last observation on June 1, 1821. His strength had now left him, and to this he could not reconcile himself. As Miss Clerke puts it, “All his old instincts were still alive, only the bodily power to carry out their behests was gone. An unparalleled career of achievement left him unsatisfied with what he had done.... His strong nerves were at last shattered.” After a prolonged period of failing health he died at Slough, at the age of eighty-three, on August 25, 1822. On September 7 he was buried in the church-yard of St Laurence at Upton. On his tombstone are engraved the words—“Coelorum perrupit claustra”—he broke through the barriers of the skies.

The death of her brother was a terrible blow to Caroline Herschel. Expecting to live only a twelvemonth, she returned to Hanover to the home of her brother, Dietrich Herschel. But she lived twenty-five years among people who cared nothing for astronomy. She was delighted at Sir John Herschel’s continuation of his father’s work. She compiled a catalogue of all the clusters and nebulÆ observed by her brother, for which she received the gold medal of the Astronomical Society, and she was created an honorary member. In 1846 she received from the King of Prussia the gold medal of science. But no honours made her in any way elated. She always held that whoever said much of her said too little of her brother. After a prolonged decline of health, she died on January 9, 1848, aged ninety-seven years, and was buried beside her father in the churchyard of the Gartengemeinde at Hanover, leaving behind her a noble example of self-sacrifice and devotion.