Illustration of the German-British astronomers William Herschel (1738-1822) and his sister Caroline Herschel (1750-1848). They are making the observations which led to the discovery of the planet Uranus in 1781. William financed the construction of this 50cm telescope with which he also discovered two satellites of Uranus (Titania and Oberon) and two of Saturn (Mimas and Enceladus). Caroline helped to prepare his catalogues and reports. She found 8 new comets between 1786-97, 3 new nebulae in 1783 and revised Flamsteed's star catalogues to make it easier to use. Illustration from Astronomie Populaire (1880).