William Herschel was born in Hanover, Germany at a time when the city belonged to England under the rule of George II. As Herschel's father was a musician in the Hanoverian army, Herschel himself was trained in music in order to enter the same profession. The Seven Years' War, however, made military life an unattractive option, and in 1757 Herschel arrived in England, where he began working as an organist and music teacher. Herschel learned of astronomy through his interest in the theory of music and the scientific basis for musical sounds, which led him to mathematics and then optics.

Newton's treatise on optics inspired Herschel with his desire to study the stars. Unable to find a telescope of a high enough resolution, he decided to grind his own lenses and to design his own instruments; he was helped by his sister Caroline, who came to England in 1772. Herschel's...