9-over-6 windows

The large windows at Belle Grove were practical as well as beautiful. The house was positioned so the majority of the windows faced east and south, maximizing the light in rooms otherwise lit by oil lamps and candles.

Features of note:
nine-over-six double-hung sash, with top sash fixed in place.
through mortice and tenon construction secured by pegs(illustrated at right).
Three wooden blocks are laid in place of bricks on each side of the jambs at Belle Grove, to provide anchor material for nailing.
decorative wood lintel above windows is set into the brickwork.

sash - a wooden or metal frame for holding window panes, which slides vertically or horizontally within a frame. In the example of Belle Grove’s windows, 9-over-6 refers to the number of panes in the top sash (9) over the number of panes in the bottom sash (6). double-hung - two sashes hung in one frame, allowing the window to open by sliding one or both sashes. sill - A horizontal timber that is the lowest horizontal part of a frame of a window or door. jamb - one of the vertical sides of a doorway, window, or other wall opening. lintel - A horizontal structural element of wood, stone, or iron spanning an opening. The lintel rests on the jambs of the opening, linking them together and supporting the weight of the wall above.

Definitions are from:
Lounsbury, Carl R. An Illustrated Glossary of Early Southern Architecture and Landscape. New York: Oxford University Press, 1994.