Began to fashion his own astronomical instruments (1773). Discovered the planet Uranus and was elected to the Royal Society (1781).
Became court astronomer to George III, whose endowments made possible the construction of an enormous telescope which is depicted on the seal of the Royal Astronomical Society (1782).
Elected to the American Philosophical Society (c. 1787). Remained active in the scientific community well into his old age.
Born in Hanover, Germany. Married Mary Baldwin Pitt; one son.