Thanks to Chris and Paul for their helpful replies. Just to complicate matters, I have both ADM and BT records for Daniel Quinn covering his service on HMS Acorn. I'm not sure what this means! What I don't understand is that he was already on board Acorn on the River Uruguay (and recorded on the ADM paperwork) at the time he was added to the BT paperwork. There doesn't seem to be a break of service in any of his ADM paperwork which would indicate a need for him to join the merchant service for a few years. Indeed the Acorn left Portsmouth in February 1845 and didn't return until May 1847. He first joined Acorn on 18th December 1844 - the BT record was issued on 26th August 1846. He was discharged from Acorn on 26th March 1848 according to the ADM paperwork. I can't make out the 'paid off' date on the BT paperwork. The ADM ref is ADM 38/7444 Acorn. C.,D.,O. 1844 Dec.14-1848 Aug.8. (http://discovery.nationalarchives.gov.uk/SearchUI/details?Uri=C767550). The BT number is BT 113/150 Register of Merchant Seamen. I haven't got a scanned copy of the ADM record yet (it's a photocopy and not very legible) but the BT one can be downloaded from my Skydrive (public, so no password needed). *http://tinyurl.com/ll93nk3* Puzzled of north of the border! Jo