Herschel was now bordering upon the ripe old age of eighty, and it is no wonder that, after a life of incessant study, his strength should daily diminish.  In 1822 it became painfully evident to his attached relatives and friends that the end was not far off; and on the 25th of August he passed away to his rest.  We owe an account of his last days to his sister, but for whose pious care, indeed, very little of his private life would have been known, and Herschel could have been judged only from the recorded results of his immense labours.

“May 20th.—­The summer proved very hot; my brother’s feeble nerves were very much affected, and there being in general much company, added to the difficulty of choosing the most airy rooms for his retirement.

“July 8th.—­I had a dawn of hope that my brother might regain once more a little strength, for I have a memorandum in my almanac of his walking with a firmer step than usual above three or four times the distance from the dwelling-house to the library, in order to gather and eat raspberries, in his garden, with me.  But I never saw the like again.

“The latter end of July I was seized by a bilious fever, and I could for several days only rise for a few hours to go to my brother about the time he was used to see me.  But one day I was entirely confined to my bed, which alarmed Lady Herschel and the family on my brother’s account.  Miss Baldwin [a niece of Lady Herschel] called and found me in despair about my own confused affairs, which I never had had time to bring into any order.  The next day she brought my nephew to me, who promised to fulfil all my wishes which I should have expressed on paper; he begged me not to exert myself, for his father’s sake, of whom he believed it would be the immediate death if anything should happen to me.”

Afterwards she wrote:—­

“Of my dear nephew’s advice I could not avail myself, for I knew that at that time he had weighty concerns on his mind.  And, besides, my whole life almost has passed away in the delusion that, next to my eldest brother, none but Dietrich was capable of giving me advice where to leave my few relics, consisting of a few books and my sweeper [that is, the seven-foot telescope with which she was accustomed to sweep the heavens for comets].  And for the last twenty years I kept to the resolution of never opening my lips to my dear brother William about worldly concerns, let me be ever so much at a loss for knowing right from wrong.”

Miss Herschel proceeds to note that on the afternoons of the 11th, 12th, 13th, and 14th of August, she, “as usual,” spent some hours with her brother.

On the 15th she hastened to the accustomed place, where she generally found him, with the newspaper which she was to read aloud for his amusement.  But, instead, she found assembled there several of his nearest friends, who informed her that her aged brother had been compelled to return to his room.  She lost no time in seeking him.  He was attended by Lady Herschel and his housekeeper, who were administering everything which was likely to keep up his failing strength.