1. The cubed Persian cubit = 8 Persian cubic feet (the Persian foot being half the cubit of 25·26 inches). The Persian cubic foot of water being the Persian or Greek-Asiatic talent, at its calculated value of 72·61 lb., the cubed cubit is 8 × 72·61 = 580·88 lb. = 58·088 gallons.
This was the Arab (and Hebrew) Den = 58·2 gallons, divided into
| 4 Artaba of | 14·55 | gallons | |
| each of | 4 Wuebe of | 3·6375 | „ |
| each of | 6 Saa of | 0·6064 | „ |
The Artaba was thus = 2 cubic feet, and the Saa was the qirát, 1/24 of the Artaba.
The modern Persian Artaba = 14·47 gallons.
2. The cubed Black cubit of Al-Mamūn = 34·73 gallons.
3. The cubed Black foot of Al-Mamūn = 10·29 gallons, the weight of which was the Kantar = 102·92 lb.
4. The Ardeb = 4 cubed Black feet; 4 × 10·29 = 41·168 gallons.
The measures derived from these cubed linear measures are as follows:
1. The first of these measures, the cubed Persian cubit, has been accurately preserved in the Cafiz of Tunis, which is the Den, doubled, 2 × 58·088 = 116·4 gallons. Its present standard is 116·34 gallons, and it is divided into