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

Whose "pous" (Greek for foot) ? As this article...

https://en.wikipedia.org/wiki/Pous

indicates there were many versions, all of different lengths (reminiscent of the cubit confusion).

I love this quote from the article...

"Stecchini and others propose the Greek podes are different sizes because they are divided into different numbers of different sized daktylos to facilitate different calculations."

It's hard to construct a useful measurement system when you can adjust the units to fit the work.

[Philip Davies]

Yes, but the Greek mathematicians had small feet, LOL

The Greek foot is 12 English inches. Photo to follow. I’m watching tv.

[Toolmaker51]

It's hard to construct a useful measurement system when you can adjust the units to fit the work.

Or printing lavatory signs to accommodate multitudinous genders.

[Philip Davies]

This is a Roman foot. The Roman foot is 24/25 of the Greek foot. The artefact is in the Ashmolean museum, Oxford. It is 0.96548 feet. It is known as the “Foot of Hercules.” This make Hercules 6’ 9”.

[Philip Davies]

Whose "pous" (Greek for foot) ? As this article...

https://en.wikipedia.org/wiki/Pous

indicates there were many versions, all of different lengths (reminiscent of the cubit confusion).

I love this quote from the article...

"Stecchini and others propose the Greek podes are different sizes because they are divided into different numbers of different sized daktylos to facilitate different calculations."

It's hard to construct a useful measurement system when you can adjust the units to fit the work.

There are indeed variations of the Greek foot. Neal explores the ratios between them.

[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

[Saltfever]

How did the mile become 5,280 ft?

The roman mile (mille passus) was exactly 5,000 roman feet. However, the English parliament standardized the mile in 1592 as 8 furlongs. (8 x 660 = 5,280). Yard goods (rope, yarn, etc) were purchased by the mile but taxed by the foot. The new "mile" was about a 5.5% tax increase!

[Philip Davies]

How did the mile become 5,280 ft?

The roman mile (mille passus) was exactly 5,000 roman feet. However, the English parliament standardized the mile in 1592 as 8 furlongs. (8 x 660 = 5,280). Yard goods (rope, yarn, etc) were purchased by the mile but taxed by the foot. The new "mile" was about a 5.5% tax increase!

The Romans had an odometer. The wheels were 4 feet in diameter, according to Vitruvius. He goes on to state that one revolution completed a distance of 12 and one half feet, giving a ratio of pi as 3.125 feet. Evidently, the Romans used a short foot (0.96768 English feet)for the diameter and a longer foot (0.973209) for the circumference. The 22/7 value of pi has been decreased by the same ratio as the value of of circumferential value has been increased. This, John Neal explains, is an example of 175-176 ratio frequently found in ancient measures.

[mklotz]

The Romans had an odometer. The wheels were 4 feet in diameter, according to Vitruvius. He goes on to state that one revolution completed a distance of 12 and one half feet, giving a ratio of pi as 3.125 feet. Evidently, the Romans used a short foot (0.96768 English feet)for the diameter and a longer foot (0.973209) for the circumference. The 22/7 value of pi has been decreased by the same ratio as the value of of circumferential value has been increased. This, John Neal explains, is an example of 175-176 ratio frequently found in ancient measures.

Their odometer also had an ingenious mechanism for dropping pebbles into a container to register miles traveled...

Ancient Rome: The Odometer Of Vitruv | History Of Physics