Many thanks for that update, PN.
I had a quick Google to read a little more about Nelson's 'Agamemnon' - here it is. She came to a sad end, it seems. The article also lists subsequent ships so named.
http://en.wikipedia.org/wiki/HMS_Agamemnon_(1781)
The wiki entry notes that the Admiralty seemed drawn to naming ships after classical heroes in Nelson's day. Again, I 'Googled' to remind myself about Agamemnon. It seems an odd name for a ship: Agamemnon led the Greeks in battle against Troy, but had a good deal of ill-luck at sea; and he was prepared to sacrifice his daughter and ended up getting murdered himself. No wonder the sailors changed the name to 'eggs and bacon.'!
http://www.pantheon.org/articles/a/agamemnon.html