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!
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.