William Lassell Biography

William Lassell was born in 1799 in Bolton, Lancashire, and educated in Rochdale. Lassell was a businessman in Liverpool who made quite a sum as a brewer (Liverpool was a large exporter and had quite a market for this) and merchant, which allowed him to become an astronomer, a “grand amateur” of the time. As the professional astronomers had classes to attend to and money to make, it was a sometimes advantageous position to be an amateur.  He was a Congregationalist, meaning that his practices would be unorthodox in Victorian Britain. Lassell created the modern big reflecting telescope. At the time, the Newtonian reflector had been around for 150 years when Lassell began to cast his first mirrors in 1820- Lassell’s goal was that he wanted to improve upon the problem of long-term object tracking for planets and satellites, which was near impossible with the current technology. Lassell loved Saturn and wanted to track it. In 1839, he submitted his 9-inch reflector to the R.A.S; it has a modest aperture, it had a wholly accurate tube and cast iron mount on wheels. It was requested that Lassell publish the schematics of his design, and he did so in ‘Memoirs’ in 1842. Next, Lassell made an enlarged version of the 9-inch reflector which was 24-inces; he devised a grinding and polishing machine which used steam power to most accurately work (the original mirror was again tested in 1995 and found to be accurate to within a fraction of a wavelength of light, an impressive boast.) In 1846, Lassell discovered Triton, Neptune’s largest moon. He also introduced the fact that Neptune had a ring, like his beloved Saturn. Lassell also discovered two new moons of Uranus, Ariel and Umbriel. Lassell was the recipient of the Gold Medal of the Royal Astronomical Society. He became president of the society in 1870 for two years. Lassell died in 1880, leaving a crater on the moon, a crater on Mars, and a ring of Neptune named after his legacy.