Sunday, July 2, 2023

Stratford Hall, Part II: The Geometry of the Elevations

Stratford Hall, begun in 1736 - As visitors would have seen it when they came to the house from the plantation's docks on the Potomac River.


My first post on Stratford Hall* looked at the how the foundation plan was composed of 5 equal squares. The location of the central hall which runs between the chimneys was also shown to be sited by the circle that laid out the squares.

The Master Builder, William Walker,** seems to have used  the square as his geometry to layout the house.  Did he use the square for the rest of the plans and elevations?  I obviously think he did, but we have few notes, only his actual construction as proof.


Was the width of the chimney bases determined by those squares?

Probably. The exterior dimensions of the house foundation and the chimney bases would have been set at the same time. Here are the Lines which divide the width of the square into 4 parts: one part on each side for doorways, 2 parts in the middle for chimney masonry.  The Lines are not quite accurate: note the red lines with arrows. Perhaps this is because the masons who built fireplaces had different skills than those who laid brick walls and the dimensions were not as critical. 



 Note that these Lines, when I added them to the square based on the inside of the brick walls, give no useful information.



A brick wall can be measured from the outside or the inside.

 A garden wall needs 2 parallel Lines (twine) to be staked - one on each side of the wall - to guide the construction.

 A brick wall for a building would also have 2 Lines. The bricklayer, checking his Lines for a building layout must decide which side of the wall to use.




At Stratford Hall a square and its lines define the exterior dimensions; they sets the size of the wing from ground to ridge pole at the top of the square (A).  The third points (B) mark the height of the brick walls which is the location for the  plate for the roof trusses. 

The lines which divide the square into 4 equal section locate the width of the chimney stack - note where they cross (C) in the middle of the square.





The lines of the square, based on the width from the interior side of the brick walls, cross at the floor-to-floor height of the lower level (D). This dimension tells the mason where the joist pockets for the floor joists to carry the main floor should be located. 

The central space of the house is the Hall, the place to gather and entertain. See my previous post for floor plans.*

Here the square is based on the inside dimension: brick wall to brick wall, just as it was for the wings. 

The geometry of the wings (the drawing above) applies here too: the location of the main floor and the height of the walls is the same.

The ceiling of the Hall is vaulted: a tray ceiling, sloped on all 4 sides. The height of the ceiling is not arbitrary but is determined by the height of the walls. 

 A red line encloses the hall and its ceiling;

The scale on the right side shows the wall height divided into 4 parts. The height of the sloped part of the tray ceiling is 1 part.   

4 parts = wall height, 5 parts = floor to ceiling.  

The Master Builder could have used the floor of the hall as a framing floor for this ceiling, making the height simple to calculate. 

At this small size the diagram of the square and its lines gets messy. So I chose a different way to show the relationships. 


* My first post on Stratford Hall:

** For a biography of William Walker see He was a Scotsman, probably trained as a joiner and wright in Scotland, who immigrated to Virginia before 1730. He would have known of the work of James Gibbs and Colen Campbell. He might have known them.





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