William Lassell (1799-1880), British astronomer. Lassell made his fortune in the beer industry, and proceeded to build his own telescope. In 1846, he discovered Triton, the largest moon of Neptune. He also discovered Ariel and Umbriel, moons of Uranus. He was awarded the Gold Medal of the Royal Astronomical Society (1849), and the Royal Medal of the Royal Society (1858). He was President of the Royal Astronomical Society (1870-1872). Craters on the Moon and Mars, and one of Neptune's rings, are named in his honour.