William Lassell (18 June 1799 – 5 October 1880) was an English merchant andastronomer.[1][2][3][4][5][6] He is remembered for his improvements to thereflecting telescope and his ensuing discoveries of four planetary satellites.
William Lassell was born inBolton, Lancashire, on 18 June 1799. He received his early education in Bolton and later attendedRochdale 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 beerbrewer, which afforded him the means to pursue his passion forastronomy. He built an observatory at his house "Starfield" inWest Derby, a suburb ofLiverpool. There he had a 24-inch (610 mm)aperture metal mirror reflectortelescope (aka the "two-foot" telescope), for which he pioneered the use of anequatorial 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, toBradstones.
In 1855, he built a 48-inch (1,200 mm) telescope, which he installed inMalta because of the observing conditions that were better than in often-overcast England. While in Malta his astronomical observing assistant wasAlbert Marth. On his return to the UK after several years in Malta, he moved toMaidenhead 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 toRoyal Observatory, Greenwich in the 1880s, but eventually dismantled.[9]
Lassell died inMaidenhead 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 theRoyal Observatory in Greenwich.
