Antique BF Goodrich TIRE INFLATION GAUGE Caliper Scale! - eBay (item 310061358966 end time Jun-27-08 18:20:14 PDT)
This antique tool was used to measure tire inflation before there was a way to measure pounds per square inch air pressure. It's marked, "Goodrich Inflation Gauge, B.F. Goodrich, Akron Ohio."
The instructions include two diagrams showing the gauge measuring a tire's narrow width at the top where it's off the ground, and fatter width on the ground. There's patina obscuring some words but I think it says:
To determine proper inflation under present load, fit caliper to tire. Refer to "Size Scale." Transfer slide to correct loading letter on "Load Scale." Place caliper at width of deflection on ground and inflate or deflate as case demands. The Size Scale of Tire scale runs from A to N. The Scale on Ground scale runs from A to L. I can't get the sliding part to slide, either because there's a trick I don't know or because there's patina holding it fast. There's a shinier place to the right which indicates it was covered and protected from patina, proof the slider did slide before. The legs unfold easily enough.
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