Postby blakstone » Sun Apr 17, 2011 12:48 am
It is not. You have to make sure you are using the correct list corresponding to the marks on the piece; the département numbers were different for each series of marks in 1798, 1809 & 1819. (Département numbers were not used in the marks from 1838.) The Empire in particular saw a large expansion of départements as parts of present-day Belgium, Italy, Germany, Switzerland, Luxembourg and the Netherlands were annexed to France.
I do have a "master list" which I have compiled that shows the numbers of each assay office during each period, as well as their opening and closing dates: the Carcassonne office, for instance, opened on 6 Apr 1799, was #11 in 1798 & 1809, #10 in 1819, and closed on 26 Mar 1862. I'd offer to post the full list, but I would have no idea how to do it: it has nearly 200 offices on it, each with up to six different numbers or codes (including the Empire-era lettered offices, the complicated regional codes of 1819 and the post-1838 cyphers.)