After a thorough investigation of the cellar’s surviving ca. 1797 framing, it was discovered that the space was divided into four separate rooms.  The longest partition ran north-south across the entire cellar and was installed against a series of large posts that supported the first floor.  Because these large posts were part of Montpelier’s structural system they were installed using stronger, more stable full mortises.  However, the two remaining partitions, which were perpendicular to the larger partition, were not framed with large posts.  Instead they used smaller, non-structural studs and because these studs were not structural, President Madison’s carpenters installed them using weaker lap mortises.