I have added links here to my blog posts that explore and add context to these ideas. I will add more.
Edward Shaw's book includes these engravings.
The cover of his book shows the tools of a Master Builder (an architect) and his workmen.
My blog posts on Shaw are here:
This post puts him in context: https://www.jgrarchitect.com/2019/10/portraits-of-master-builders-with-their.html
This post discusses his tools, and those of others, in detail.
I have not explored the geometry of this door, nor the elevation below it.
These drawings with notes about the degree of roof pitch show how the Classical language of the Renaissance was no longer the standard as the Industrial Revolution began.
Pediments had a 4/12 roof pitch 22.5*. Now, as you can see, maybe not.
Perhaps the change in roof pitches was due to the availability of tin roofing sealed with lead. Before that 'roofing' was wood shingles which required at least a 4/12 (22.5*) pitch.
Slate roofing tiles were used in the UK, and in Europe. That technology was not here until the late 1840's.
Carpenters who had trained under Master Builders before the Civil War now became 'architects': designers who knew construction intimately and worked closely with their contractors.
Colleges began to teach and graduate people who were architects. However their drafting tools were almost identical to those used in 1750 by Master Builders.
We were still using practical geometry, and we were still passing it on as much by learning from a master trades person, perhaps an architect, as by reading about it.
Looking at these images: While I can see their geometry, I have not studied it.
The second is from Rossiter, E.K. and Wright, F.A. *Authentic Color Schemes for Victorian Houses, Comstock's Modern House Painting, 1883.
The third is from Shoppell, R.W. et al., Turn-of-the Century Houses, Cottages and Villas, NYC, c. 1900.
The * indicates a Dover Publications reprint.
The bibliography for the presentation is here: https://www.jgrarchitect.com/2022/03/a-bibliography-for-my-traditional.html