Pouring anchor Kenter shackle lead plug - GIF

[mklotz]

“One second of arc of the meridian degree is 100 Greek feet.”
This quotation is from “All done with mirrors” by John Neal

Very close, if the Greek foot was close to the inferial foot...

3959 miles (earth radius) * 2pi * 5280 (ft/mile) / (360 * 60 * 60) = 101.34 ft/arcsecond

Of course, we don't know what they used for the earth radius. (At least they knew it was a sphere and didn't think it was flat.)

[Toolmaker51]

Very close, if the Greek foot was close to the inferial foot...

3959 miles (earth radius) * 2pi * 5280 (ft/mile) / (360 * 60 * 60) = 101.34 ft/arcsecond

Of course, we don't know what they used for the earth radius. (At least they knew it was a sphere and didn't think it was flat.)

Might be my favorite distillation of mathematics, dependent on observation AND science. Epic, with Venetian cartographers and Portuguese sailing captains ignore all of it. Their concept held Earth barely half the actual and proven diameter.

https://www.aps.org/publications/aps...06/history.cfm