The bare bones of the story of William Herschel are well known: he was a German musician who came to England, took up astronomy, and discovered the planet Uranus. Oh yes, and he had a sister who helped him out a bit. All this is true; but, as Michael Hoskin’s delightful book makes clear, it is not the whole story.

The first clue is given by the plural in the title. Although Caroline Herschel was definitely number two in the partnership, they certainly made a team, and William could never have achieved as much as he did without her. The rest of the title hints at what lifts