The royal foot, 2/3 of the cubit, = 13·76 inches.
The foot cubed = 2605 cubic inches; 2605/27·73 = 93·9 lb. as the calculated weight of the standard afterwards known as the Alexandrian talent.[[5]]
The actual weight was 93·65 lb. = 655·550 grains; 655550/3000 = 218·5 grains was the weight of the shekel, nearly our half-ounce—exactly the half-ounce of Plantagenet times, and very near to the weight of our half-crown, which weighs 218·18 grains.
The difference between calculated weight and the actual weight determined from coin or other standards, from trustworthy historical statements and other sources of information or of evidence, is generally due to the great difficulty in constructing accurately the cubical vessel used to ascertain the weight of a cubed measure of water. A difference of 2/100 of an inch in the sides of the vessel made to hold a royal cubic foot of water would make a difference of about 3 parts in 1000, of 4-1/2 of the 1500 ounces or double-shekels of water it contained. And we do not know the temperature of the water used.
From the ancient and medieval cubits were derived all the weights and measures of medieval and modern civilisation, largely through the medium of the talents derived from these standards.
| From | the | Egyptian | common | foot | came | the | Olympic Talent | |
| „ | „ | „ | royal | „ | „ | „ | Alexandrian | „ |
| „ | „ | Great Assyrian | „ | „ | „ | Greek-Asiatic | „ | |
| „ | „ | Arabic | „ | „ | „ | Arabic | „ | |
1. The Alexandrian Talent
The standard of this talent has been already given as 93·65 lb., which × 7000 = 655,550 grains.
It was divided on different systems:
1. By the Chaldæans and Egyptians into 60 minás, divided—