Caroline would feed him and read to him as he worked, despite her desire to burnish her career as a professional singer. She became a significant astronomer in her own right as a result of her collaboration with him. The Herschels moved to a new house in March 1781 after their millinery business failed, and Caroline was guarding the leftover stock on 13 March, the night that William discovered the planet Uranus. Though he mistook it for a comet, his discovery proved the superiority of his new telescope. Caroline and William gave their last musical performance in 1782, when her brother accepted the private office of court astronomer to King George III; the last few months of their musical career had been a shambles and were critically panned. William's interest in astronomy started as a hobby to pass time at night. At breakfast the next day he would give an impromptu lecture on what he had learned the night before. Caroline became as interested as William, stating that she was "much hindered in my practice by my help being continually wanted in the execution of the various astronomical contrivances." William became known for his work on high performance telescopes, and Caroline found herself supporting his efforts. Caroline spent many hours polishing mirrors and mounting telescopes in order to maximize the amount of light captured. She learned to copy astronomical catalogues and other publications that William had borrowed. She also learned to record, reduce, and organize her brother's astronomical observations. She recognized that this work demanded speed, precision and accuracy. Caroline was asked to move from the high culture of Bath to the relative backwater of Datchet in 1782, a small town near Windsor Castle where William would be on hand to entertain royal guests. He presumed that Caroline would become his assistant, a role she did not initially accept. She was unhappy with the accommodations they had taken; the house they rented for three years had a leaky ceiling and Caroline described it as "the ruins of a place". She was also aghast at the prices in the city and the fact that their domestic servant was imprisoned for theft at the time of her arrival. While William worked on a catalogue of 3,000 stars, studied double stars, and attempted to discover the cause of Mira's and Algol's variability, Caroline was asked to "sweep" the sky, meticulously moving through the sky in strips to search for interesting objects. She was unhappy with this task at the beginning of her work, longing for the culture of Bath and feeling isolated and lonely, but gradually developed a love for the work.