Her brother William [q. v.], to whom she was from the first enthusiastically attached, now offered her a home at Bath, and she prepared herself for singing at concerts by imitating the violin parts of concertos with a gag between her teeth. In this way she ‘gained a tolerable execution’ before she attempted to sing. She reached Bath on 28 Aug. 1772.
Besides giving her two singing lessons daily, her brother taught her English and arithmetic; but her studies were from 1773 impeded by continual demands for aid in his astronomical pursuits. The summer of 1775 was ‘taken up with copying music and practising, besides attendance on my brother when polishing, since, by way of keeping him alive, I was constantly obliged to feed him by putting the victuals by bits into his mouth.’ Moreover, she read novels to him while he was at the turning-lathe or polishing mirrors, serving his meals without interrupting the work with which he was engaged, and sometimes lending a hand. ‘I became in time as useful a member of the workshop as a boy in the first year of his apprenticeship.’
Meanwhile, as a preparation for appearance in oratorios, she was being ‘drilled into a gentlewoman’ by a dancing-mistress; her brother presented her with ten guineas to buy a dress, and she was pronounced at her début ‘an ornament to the stage.’ Her success was considerable. As first treble in the ‘Messiah,’ ‘Judas Maccabæus,’ &c., she sang at Bath or Bristol sometimes five nights in the week, but declined an engagement for the Birmingham festival, having resolved to appear only where her brother conducted. Their last public performance was in St. Margaret's Chapel, Bath, on Whit-Sunday, 1782.
At first she grudged the abandonment of music in order to be ‘trained for an assistant-astronomer.’ She began ‘sweeping’ on her own account with a small Newtonian reflector on 22 Aug. 1782 at Datchet, and in the following year discovered three remarkable nebulæ, one of them the well-known companion to the Andromeda nebula (No. 105 of Sir J. Herschel's ‘General Catalogue’). From December 1783 she was absorbed in the arduous labour of assisting her brother. Her presence when he was observing was indispensable. She habitually worked with him till daybreak. She not only read the clocks and noted down his observations, but executed subsequently the whole of the extensive calculations involved. She brought the stars of the ‘British Catalogue’ into zones of one degree each for his ‘sweeps,’ copied his papers, and prepared his catalogues for the ‘Philosophical Transactions,’ besides the occupations of housekeeping, needlework, and entertaining distinguished visitors. In her few leisure moments she ground and polished mirrors, and ‘was indulged with the last finishing of a very beautiful’ one for Sir William Watson.
Between 1786 and 1797 she discovered eight comets, five of them with undisputed priority. That of November 1795 was afterwards famous as ‘Encke's comet.’ Some of the data relative to them are still preserved in a packet inscribed by her ‘Bills and Receipts of my Comets.’ The faint object detected on 1 Aug. 1786 was looked at with curiosity by Miss Burney as ‘the first lady's comet.’ She described Miss Herschel as ‘very little, very gentle, very modest, and very ingenuous’ (Madame d'Arblay, Diary, iii. 442, ed. 1842). Mrs. Papendick, though less sympathetic, says that she was ‘a most excellent, kind-hearted creature’ (Journals, i. 253).
In 1787 a salary of 50l. a year, the first money which she thought herself free to spend to her own liking, was settled by the king upon Miss Herschel as her brother's assistant. After her brother's marriage, on 8 May 1788, she lived in lodgings, but co-operated with him no less zealously than before. The change, though bravely borne, cost her severe pangs. On 8 March 1798 her ‘Index to Flamsteed's Observations of the Fixed Stars’ was presented to the Royal Society, and was published at their expense with her list of ‘Errata’ to the same observations. The usefulness of a work which ‘contains a reference to every observation of every star in the British Catalogue’ was cordially acknowledged by Baily (Life of Flamsteed, pp. 388, 390).
In August 1799 Miss Herschel spent a week at the Royal Observatory, as the guest of Dr. Maskelyne; and from July to November 1800 she was at Bath, setting Alexander Herschel's house in order. Her youngest brother, Dietrich, came to England in broken health in 1805, and she was much tried for the next four years by adding care for him to her other occupations. Miss Herschel was present at royal fêtes at Frogmore in 1816 and 1817, and saw much of the Princess Sophia in the autumn of 1818. From 1819 her brother William's health caused her much anxiety. She assisted him in observing for the last time on 21 June 1821, and in the impetuosity of her grief for his death on 25 Aug. 1822, she carried out a hasty resolution to spend the remainder of her life with her relations in Hanover.
She regretted too late having ‘given herself and all she was worth’ to the German branch of her family, but would not ‘take back
