William Lassell was a Liverpool brewer, whose success in the brewing business gave him the leisure to pursue an interest in astronomy. He designed and built his own reflector telescope, which was innovative in its being mounted in the equatorial plane - this meant that he could track objects as they moved through the sky more easily than previous astronomers had done. When Neptune was discovered in 1846 by Galle in Berlin, known as 'Le Verrier's planet' because Galle had used the French mathematician's calculations to find it, Lassell soon trained his telescope on the new planet. His impressive telescope also showed that Neptune had a ring, like Saturn, and a moon, which came to be called Triton.
Editors. "Triton discovered by William Lassell". The Literary Encyclopedia. First published 30 August 2013
[http://www.litencyc.com/php/stopics.php?rec=true&UID=6298, accessed 26 September 2016.]