Soon after the death of him to whom she had given up so much of her life, her best energies, and her ripest faculties, she returned to Hanover,—unwilling, however, to relinquish the astronomical researches which had been so pure and permanent a source of pleasure. She undertook and completed the laborious "reduction" or registration of the places of 2500 nebulae, down to the 1st of January 1800; thus presenting in one view the results of all the observations Sir William Herschel had made upon those wonderful bodies, and triumphantly bringing to a close half a century of scientific toil.
We return to Miss Herschel's biography, in order to gather up a few particulars of her last years, and to exhibit some of the tenderer features of her character.
On the occasion of her nephew's marriage, in 1829, she wrote to him in the following terms:—
"MY DEAREST NEPHEW,—I have spent four days in vain endeavours to gain composure enough to give you an idea of the joyful sensation your letter of February 5th has caused me. But I can at this present moment find no words which would better express my happiness than those which escaped in exclamation from my lips, according to Simeon (see St. Luke ii. 29), 'Lord, now lettest thou thy servant depart in peace.'
"I have now some hopes of passing the few remainder of my days in as much comfort as the separation from the land where I spent the greatest portion of my life, and from all those which are most dear to me, can admit. For, from the description given me of the dear young lady of your choice, I am confident my dear nephew's future happiness is now established.
"I beg you will give my love to your dear lady, and best regards to all your new connections where they are due, in the best terms you can think of, for I am at present too unwell for writing all I could wish to say.
"I have suffered much during this severe winter, and have not been able to leave my habitation above three or four times for the last three months; and feel, moreover, much fatigued by sitting eight times within the last ten days to Professor Tiedemann for having my picture taken—which he did at my apartment, and now he has taken it home to finish. I must conclude, for I wish to say a few words to your dear mother. It is now between eleven and twelve, and perhaps you are at this very moment receiving the blessing of Dr. Jennings; in which I most fervently join by saying, 'God bless you both!'"
Though eighty-three years old, Miss Herschel retained all her old powers of memory; and in a letter to her new niece, Lady Herschel, written in 1833, she narrated some amusing reminiscences of her nephew's early childhood.
He was only in his sixth year, she said, when she was separated for a while from the family circle. But this did not hinder "John" and her from remaining the most affectionate friends, and many a half or whole holiday he spent with her, devoting it to chemical experiments, in which all kinds of boxes, tops of tea-canisters, pepper-cruets, tea-cups, and the like, served for the necessary vessels, and the sand-tub furnished the matter to be analysed. Miss Herschel's task was to prevent the introduction of water, which would have produced havoc on her carpet. For his first notion of building, "John" was indebted to the affection of his aunt, who, on his second or third birthday, lifted him in the trenches to lay the south corner-stone of the building which was added to Sir William's original house at Slough. On further reflection, she felt convinced that this incident occurred in the second year of her nephew's age, for she remembered being obliged to use "a deal of coaxing" to make him part with the money he was to lay on the comer-stone.