Star Tool Co. Marking Gauge
For some, the mention of Fibonacci may evoke a picture of a
new gourmet pizza, a plate of exotic Mediterranean food or a
high-powered racing vehicle. However, what Fibonacci is best
known for is the number sequence that bears his name. It runs
0, 1, 1, 2, 3, 5, 8, 13, et cetera, with each number the sum of the
two preceding numbers. When these are plotted as increasing
distances from the origin, they form a spiral. In nature an
example of it is the nautilus shell.
What does this have to do with the tool shown below? Wessel
Brodhead of Meadville, Pennsylvania, may have found that spiral
his inspiration for the shape of the locking mechanism in his
carpenter's gauge or maybe he simply had a personal revelation.
|Spiral-shaped locking mechanism
||Close-up of brass fittings
On April 21, 1868, he applied for patent #76,884 for his invention.
The patent description is extremely brief and, unlike other
marking devices of the time, it did not use a wedge or screw
in the gauge's adjustment. The mechanism, or lack thereof, is
described as an elliptical or cam-shaped rod meshed with a corresponding
hole in a headpiece. Simply twisting the two pieces together
caused a firm and secure lock. And unlike most patents employing
proprietary processes, Brodhead actually described his gauge's
construction method in the patent papers.