The Moore House* photographed by Henry Glassie, built before 1750.
This house has 2 rooms up and down, 2 fire places, 2 chimneys, and a shed on each end. The main block is double the size of the house I wrote about in Part1: https://www.jgrarchitect.com/2022/11/virginia-folk-housing-update.html
The geometry begins as it did in Part 1, using the width as the circle's radius.
Here is the floor plan: 2 rooms with fireplaces, and sheds on both ends.
The daisy wheel for this house begins with the left wall of the main house.
That wall's width is the radius, 1-6. A is the center of the circle. The daisy wheel lays out the other 4 points, 2, 3, 4, 5.
Lines 1-3 and 6-4 are the sides of the house. 2-5, the diameter of the circle, lays out the interior wall.
Lines 1-5 and 2-4 can extend forever. Where is the right end wall of the house located? Where is C?
It's at the end of the circle, but that's only a point, not a line. 2 points are necessary to draw a line to mark the right end of his foundation and the floor of the house.
If the carpenter extends his arcs he can quickly find the missing points.
Extend the arc centered at 3 (2-A-4) to B. The arc centered at 4 (5-A-3) crosses the earlier arc at B. He has 2 points: A and B, And can draw line A-B.
Now C is fixed at the intersection of A-B. C is the center of a new arc, (7-A-8). The extended arc from 5 (6-A) crosses at 7. The arc 2 (1-A) crosses at 8. 7-C-8 locates the right wall.
C also locates the center of the fireplace and the chimney.
The daisy wheel is often dismissed as a design tool. It is flexible, quickly drawn, and accurate.
The geometry comes from the first length - the width chosen by the owner and builder for this house. That width, and the house, could be bigger or smaller to suit the owner's needs and budget, as well as to the lumber available for joists and rafters.
Once the carpenter decides on a width he uses one compass setting, one radius, for the whole layout. Every point is checked. As the lines are marked, the diagonals can prove the layout to be true.
If he drew a layout at a smaller scale, he could easily step off to full-sized construction dimensions with his compass. He could also draw the layout on the ground, stake the points and mark the wall locations with twine just as framers and masons do today.
Consider how the plan would be laid out if the circle is not used. Use a 10' pole - a common tool of the time. Each corner would need to be figured independently; every dimension stepped off separately, and with what accuracy?
The daisy wheel locates all angles and lengths quickly. It has built-in checks from the beginning and as the layout progresses: if the circle doesn't close, the 6 points will be uneven, the arcs won't cross, the diagonals will not match. The layout will not be accurate.
Both wings are 3/4/5 rectangles. See the left shed. The floor plans of wings were usually 3/4/5 rectangles so that they would sit square to the existing house. All the joists would then be the same length; as would be the rafters.
My earlier complex geometry 'works'; the lines are there. But they don't give the basic information the builder needs: the dimensions of the foundation, the floor plan, the size of the house.
*The Moore House, Fig. 31, Type 5, p, 77; the photograph: p.76.
Henry Glassie, Folk Housing in Middle Virginia, U Tennessee Press, 1975; plans, drawings and photographs by Henry Glassie.