Hello
Jane Griswold Radocchia is an architect.
Jane studies practical geometry and vernacular architecture.
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Below are some of her latest blog posts, some others can be found on this web site's Archive
Jane Griswold Radocchia
Jane Griswold Radocchia
Up Coming Events
Next Presentation:
Compasses and Carpenter Squares
At the EAIA Annual Conference
Rochester, NY
May 31, pm.
3:30-4:30 pm.
EAIA: Early American Industries Association
Tuesday, May 13, 2025
The Carpenter Square and the Compass - The Evolution of Practical Geometry
On May 31, 2025, I will present Practical Geometry and Carpenter Squares at the Early American Trades Association (EAIA)* conference in Rochester, New York. I will talk about how the use of a carpenter square for many layout decisions - using a 3/4/5 rectangle instead of a circle - changed the visual character of our architecture.
What happened after 1820 when the carpenter square became a reliable drafting tool? When the compass, line, and scribe were joined by an L shaped piece of steel with a dependable, true 90* corner?
The squares shown here were made in Vermont c. 1830-50. They now live at the Bennington Museum, Bennington Vermont, and can be seen by appointment.
Here you can see the hand stamped numbers on the earliest squares as well as carefully drawn scales.
The square made design and layout accurate with fewer steps. That meant it took less time to draw and measure work. However, little by little the accessibility of a true 3/4/5 triangle became a design element as well. Here's an example.
Robert Shaw's The Modern Architect was published in Boston in 1854.** This is Plate 4, a 'Grecian Frontispiece'. The main door is laid out as a square.
I've added the scales on the bottom and right side. It is 8-1/2 units wide and tall. The door is 3 units; the pilasters are a half unit. The sidelights are 1 unit; the columns are 1-1/4. The columns' capitals are a half unit.
The red quarter circle arcs of the width cross at the top of the door frame, just below the transom. This layout choice can been seen much construction pre-1820.
The whole frontispiece is a square plus its diagonal tall. The height is equal to the diagonal of its width.
This proportion is also used for the sidelight glass panes (see the image above), but not those in the transom>.
Shaw writes that the door's height should be "...over twice the breadth of its height as three and seven feet."* It is also a shape drawn easily by the carpenter square.
The door and its columns taken together become a simple 3/4/5 rectangle.
I think when we architects, crafts people, and historians note from visual observation that a particular building is Greek Revival, not Late Georgian, we are seeing geometry. We recognize the compass based proportions of Federal architecture and then the changing proportions of Greek Revival. We haven't understood how the tools of practical geometry's created what we perceive.
* EAIA, Early American Trades Association https://www.eaia.us/
https://www.eaia.us/2025-rochester-ny
** Robert Shaw, The Modern Architect, Boston, 1854, originally published by Dayton and Wentworth, republished (unabridged) by Dover Publications in 1996.
*** Shaw, The Modern Architect, page 63.
Architect
As an architect based in Bennington, VT. and Andover, MA. I work with old houses and the families who love them.
During this time, I have worked with over 1200 houses, some modern, some 300 years old.
Historian
I am an architectural historian by accident. I found I was showing friends and clients the historic environment they lived in but did not see.
I know from my work as an architect how available materials and technology influence design and construction.
I am most interested in vernacular architecture, how we built to suit our climate and our needs using the tools and materials we had.
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Blogs
Architecture (Current Blog)
Passing By (Original Blog)
Sunday Drives (Original Blog)
Comments / Reflections
Mary said...
Thank you so much for this lovely article. This church was well loved & had at least a dozen families attending when it closed down. It is sad to see it be torn down, instead of being preserved as a community space. The one blessing is that we can finally see the beautiful architectural elements you describe, which were hidden to all of us by the drop ceiling. Lovely that the church still stands in this elemental fashion for a few more months. More
