Thanks Kev.
Chris, Dunlop is credited with the discovery, or first sighting, of the magnitude 4 "Great Comet" of 1833, C/1833 S1 Dunlop.
He also helped recover Comet Encke in 1822, tracked Comet Pons in 1825-26 and followed Halley's comet in 1835.
http://books.google.com.au/books?id=...201833&f=false