The existence of a revolving serving door between the Dining Room and the north passage is confirmed in Cornelia Jefferson Randolph's floor plan of Monticello, where it is called a "turning buffet." Robert Mills' floor plan, conjecturally dated 1803, includes the serving door. Visitors to the President's House in Washington also reported Jefferson's use of such a device there.
The door is located in a recess of the dining room near the stairs that led to the kitchen, allowed servants to remove empty serving dishes from the first course and to place foods for the second course on the shelves and rotate the door into the Dining Room. Stationed in the Dining Room, one or more servants or family members could transfer the food from the serving door shelves to the table.
The current serving door was constructed in 1949, based on an existing door at John Hartwell Cocke's Bremo. As for precedents, such doors call to mind similar devices in convents, which Thomas Jefferson would have seen in Europe. It is certainly possible that they were a feature of some of the houses he frequented in Paris. Note also that Benjamin Latrobe incorporated such serving doors in his own house designs from at least September 1805, when he completed the plans for Thomas Worthington's Adena. If Fiske Kimball's 1789-1794 dating of the above mentioned designs is correct, however, Jefferson considered using revolving serving doors well before Latrobe's arrival in America.
1. This article is based on Lucia Stanton, Monticello Research Report, 1991.