The next great change in the life of the brother and sister took place in 1782, when William Herschel left Bath and was appointed Astronomer-Royal by George the Third. His salary of only £200 a year involved a great loss of income, but this, in his eyes, was a small matter in comparison with the advantage of having his time entirely free to give up to his favourite studies. They bade farewell to Bath, and settled first at Datchet, shortly after, however, removing to Slough. Caroline had dismal visions of bankruptcy, but William was in the highest spirits, and declared that they would live on eggs and bacon, "which would cost nothing to speak of, now that they were really in the country."
Caroline was now installed as an assistant astronomer, and was given a telescope, which she calls a "seven-foot Newtonian Sweeper"; and she was instructed, whenever she had an evening not in attendance on her brother, to "sweep for comets"; but her principal business appears, at this time, to have been waiting on her brother, and writing down the results of his observations; they worked quite as hard as they had done at Bath. They laboured at the manufacture of instruments all day, and at the observation of the heavens all night. No severity of weather, if the sky was clear, ever kept them from their posts. The ink often froze with which Caroline was writing down the results of her brother's observations. It has been well said that if it had not been for occasional cloudy nights, they must have died of overwork. The apparatus for erecting the great forty-foot telescope, and the iron and woodwork for its various motions, were all designed by William Herschel, and fixed under his immediate direction. His sister, in her Recollections, wrote: "I have seen him stretched many an hour in the burning sun across the top beam, whilst the iron-work for the various motions was being fixed." The penurious salary granted to William Herschel was supplemented by special grants for the removal and the erection of all this machinery; and in 1787 Caroline's services to her brother were publicly recognised by her receiving the appointment of assistant to
