Tuesday, June 13, 2023

Stratford Hall, Part I: Paul Buchanan's Ideas

This post is an introduction to my understanding of the geometry of  Stratford Hall, the plantation and home of the Lees of Virginia for 4 generations  beginning in 1736.

Here is the house as it looked this spring when I was there for 3 days. 

In the gift shop I found the book  Paul Buchanan Stratford Hall.* Of course I bought it.

The book focuses on Buchanan's  research at Stratford Hall from 1984-1993, after it introduces us to his historic preservation work at Colonial Williamsburg as well as other Great Houses in Virginia, including Gunston Hall.

This image on page 14 is from one of Buchanan's favorite pattern books, The London Tradesman, by R. Campbell, published in London in 1747.

I spotted the compass leaning against the beam, and the man to the far left, probably the builder, with his rod. That led me to the book which is available online. 

It is a fascinating review of the trades in mid-18th c. London. Geometry is listed, among others, as a necessary skill. 

Chapter XXXI, Of Architect and those employ'd in that Branch, lists the skills men need to succeed in that profession.  Campbell writes that an architect's "head (must be) Mathematically and Geometrically turn'd."  and "Besides this Plan he generally forms a Model in Wood." pages155-6

For a stone mason, "Geometry is absolutely necessary". page158

For a carpenter: "He must understand as much Geometry as related to Measuration (the act of measuring) of Solids and Superficies (surface areas)". page 160

For a joiner: "His Business requires that he should be acquainted with Geometry and Measuration". page 161  

Of course I wanted to understand how Buchanan applied this, what he knew about the geometric skills listed by Campbell. I study how our ancestors used geometry as a practical tool for construction, as well as for design.

Using the HABS drawings for the house, done in 1969, Buchanan overlaid squares and a circle.

His squares 'work': they fit. However they do not tell us much about how to build the house. They do not provide clear and simple information - the layout of the plan, the size of the spaces and their relationship to each other - for the Master Builder who, at Stratford Hall, was William Walker.


I used the width of the wings as the dimension of a square to lay out the foundation plan using 5 squares. The middle square is centered between the 2 wings. The foundation would have been easy to layout with compasses, and a rod, both of which are in Campbell's illustration.



Twine, also essential, is not in the illustration. Maybe it was too skinny - just a line. (A deliberate pun: twine marks the 'Line' - as in 'chalk line'- which the builder needs in order to build.)

Here is the width of the east wing used as the radius for a circle, drawn in red. The 6 points of the circle locate the square, drawn here in black

I drew this for the readers of this post who might not know how a daisy wheel can be used. In the process I saw that the foundations for the fireplaces are also located, see the black dashed line.

For an introduction to the use of a daisy wheel see: https://www.jgrarchitect.com/2023/01/geometry-in-construction-practical.html

* Paul Buchanan Stratford Hall and Other Architectural Studies, copyright 1998,  Robert E. Lee Memorial Association, Inc. Stratford Hall Foundation, Stratford, VA.



Wednesday, June 7, 2023

That daisy wheel you found? Please trace it for me.

 If you found a daisy wheel scribed on an old building, please trace it, copy it, and send me the full scale image with a note about where it was found, on what kind of building. 

I want to compare daisy wheels and measure their diameters. Here's why. 

The daisy wheels we find today were scribed with a compass on posts, on beams, sheathing, walls: a circle with 6 points, 6 petals, evenly spaced, drawn using the radius of the circle.

200 years ago they were a practical tool for layout and design, simple geometry, easy to use and true - accurate - in a world without fixed dimensions. Standardized dimensions came with interchangeable parts which we didn't need until the Industrial Revolution.  

Daisy wheels have been noted and copied. Rarely have we measured their diameters. Are the  diameters of daisy wheels a scale, just as the notation- 1/4"=1'O" -  is a scale? Maybe, But I can't tell from only 3 examples. I need to check a lot more! 

This is my daisy wheel and its 9 ft. long board.  It was part of an outbuilding of a barn in Vermont.The center of the wheel is  46" from the floor, a good height for a workman setting his basic dimension for his compass width (the diameter of the daisy wheel) as he began work and checking it as he needed throughout the day. It was also useful information for those who came later, expanding or repairing the farm complex.

My daisy wheel was easy to find. However, many are discovered in obscure places, on beams and roof sheathing. As a frame was cut that piece of the frame (usually sheathing) was a notice board. When the frame was raised, the wheel had served its purpose. The sheathing however, cut by hand and water power, was too valuable to discard. It became part of the frame.

This daisy wheel was on roof sheathing of a barn in upstate New York, built c. 1795. Unlike the daisy wheel above (which has deep holes at its center and at the outer points of the petals as they meet the circumference of the circle) this wheel is cleaner, probably used only for this barn, not the larger barn complex around it.

 Here is a tracing of it. 

 Both of these daisy wheels measure 8" + a smidgen. The depth and age of the scribe's grove makes precision difficult.  However: 8.25" x 2 = 16.5".  16.5" x12 is a rod, 16.5 feet.

The rods laid out by stepping off these 2 daisy wheels' diameters might differ from each other by several inches. But each frame would be consistent within itself.

A rod was a common dimension in England. It was also called a 'pole' and a 'perch'. Land surveyors still measure land in rods today. 


This daisy wheel is on the interior side of the sheathing on the second floor of the Gedney House in Salem, Massachusetts, built in 1665, expanded in 1712, and 1800, The house is now owned by Historic New England.





 The daisy wheel is quite small.




Its diameter is 5.5". 5.5" x 3 = 16.5". 16.5" x 12 = a rod.



The neat, small ones which we find may be the signature of a trained master carpenter or mason. Laurie Smith (English Geometer, 1936- 2021) showed me one carved into a stone mantle. He had found that the geometry governed the design and was also probably a signature. 


This one comes from  the Beatty-Cramer House in Maryland.The wheel diameter is 3". It and the 'eye' below it might be Masonic symbols of God and Truth, as geometry was known to be true. The understanding that geometry is 'true' was not part of my high school geometry class.  I learned that from carpenters.


Palladio wrote c.1570 that he would use the diameter of a column as his 'module', his measure for his work.  Here's his drawing: 

The column is a circle. It is laid out with a compass, Its diameter, stepped off using a compass, is the module: it measures the distance between the columns. The scribed daisy wheels that we find today are also modules.


Here he is, holding his compass.



So - if you know of a daisy wheel, can trace it, and send the tracing to me, please let me know. Thanks.

Daisy wheels are said to be apotropaic. However I have not yet read a record made by someone of the period noting the deliberate addition of a daisy wheel to a building to ward off evil. I am skeptical.