This would not prevent the new cubit, the Great Assyrian cubit, being itself in course of time cubed to form the Den measure, as its half, the foot, was cubed for its weight of water to make the Greek-Asiatic talent.
However this be, the great Assyrian cubit, which continued to be used in the Persian empire, had the advantage of being divided into 8 palms and of making a good two-foot rule, though its half, the foot, was rather too long for popular use. This cubit exists to this day in Egypt, being the basis of the Reed or Qasáb. This is the ‘full reed of six great cubits’ (Ezek. xli.), the ‘measuring rod of six cubits by the cubit and a handbreadth,’ that is the old seven-palm cubit with a palm added. The Qasáb = 151·16 inches is = 12 Assyrian feet.
Yet, for the common purposes of life, a foot = 12·63 inches was too long to be popular; everywhere the people like a short foot, especially in the South and the East. Moreover the cubit was a departure from the simple geodesic standard of the meridian cubit. Accordingly there was devised in Persia a cubit satisfactory both to the scientific class and to the people, with a simple geodesic standard for scientific purposes and a convenient short foot for the common purposes of life. This was the Beládi cubit. It is perhaps the best of the cubits.
The new Persian cubit, known as the Beládi (from _belád_, country), had the advantage, first, of a simple relation to the Parasang or meridian league of 30 stadia = 1/20 degree; secondly, of it being divisible into two feet of convenient length.
The meridian mile being = 6080 feet or 72,960 inches the parasang is therefore 3 × 72,960 = 218,880 inches; and the Beládi cubit, 1/10000 of the parasang, was therefore = 21·880 inches. This is the length that John Greaves gave in 1645 as his measurement of what he called the Cairo cubit, one of the different standards that have accumulated in Egypt during sixty centuries.
The Beládi cubit is still to be found in the East. A half Beládi cubit = 10·944 inches, a convenient foot for Eastern use, passed to Spain with the Moors and became the Burgos foot, the standard of which was allowed to go astray after the fall of the Moorish dominion. But the Spanish shore-cubit (_Covado di ribera_) still exists at the standard of 21·9157 inches.