Thanks for the info on HMS Gannet, Kester.
A bit more on Franklin - a little out of 'our period', but of interest, I think.
Franklin went on the expedition in an attempt to rescue his reputation which he felt had been damaged during a short spell as governor of Tasmania where he and Lady Franklin attracted the hostility and contempt of Hobart society for trying to improve the lot of the convict and aborigine inhabitants - another example of a humanitarian naval officer.
Lady Franklin was well supported by the generosity and courage of those who went to search for Franklin: Commander Edward Inglefield, Sir John Ross, and a French naval officer, Lt Joseph-René Bellot, who was 'endearingly affectionate' and treated as a son by Lady Franklin. He has a memorial and a street named after him in Greenwich.
http://en.wikipedia.org/wiki/Joseph_Ren%C3%A9_Bellot