William Lassell (18 June 1799 – 5 October 1880) was an English merchant and astronomer.[1][2][3][4][5][6] He is remembered for his improvements to the reflecting telescope and his ensuing discoveries of four planetary satellites.
Life
William Lassell was born in Bolton, Lancashire, on 18 June 1799. He received his early education in Bolton and later attended Rochdale Academy..[7] After the death of his father, William Lassell was apprenticed to a merchant in Liverpool from 1814 to 1821. He later made his fortune as a beer brewer, which afforded him the means to pursue his passion for astronomy. He built an observatory at his house "Starfield" in West Derby, a suburb of Liverpool. There he had a 24-inch (610 mm) aperture metal mirror reflector telescope (aka the "two-foot" telescope), for which he pioneered the use of an equatorial mount for easy tracking of objects as the Earth rotates. He ground and polished the mirror himself, using equipment he constructed. The observatory was later (1854) moved further out of Liverpool, to Bradstones.
In 1855, he built a 48-inch (1,200 mm) telescope, which he installed in Malta because of the observing conditions that were better than in often-overcast England. While in Malta his astronomical observing assistant was Albert Marth. On his return to the UK after several years in Malta, he moved to Maidenhead and operated his 24-inch (610 mm) telescope in an observatory there. The 48-inch telescope was dismantled and was eventually scrapped.[12] The 24-inch telescope was later moved to Royal Observatory, Greenwich in the 1880s, but eventually dismantled.[9]
Lassell died in Maidenhead in 1880 and is buried at St. Luke's Church.[17] Upon his death, he left a fortune of £80,000 (roughly equivalent to £10,100,000 in 2023). His telescope was presented to the Royal Observatory in Greenwich.