We must assume:
- The map from 1815 had NHM correctly located to it's present day location
- The map or a copy of the map traversed the Atlantic ocean for purposes unknown
- The map then must traverse the eastern seaboard or directly from New York Port
- The map would then have to travel within the vicinity of Joseph Smith
- Joseph Smith would then have to have reason to be exposed to the map in question
- The map itself must, by point-in-fact, impress upon Joseph the name of NHM to be remembered years later
Those seem like a lot of assumptions to get JS in contact with the map.
Do you have a proposal to remedy these assumptions?
Some of those assumptions are quite silly but this is a good example to show what I've been saying and you apparently haven't bother to read. I'll take ALL of these assumptions and I still am in more solid of a ground that he who takes super-natural assumptions (LDS believers).