Page:The Rhind Mathematical Papyrus, Volume I.pdf/47

 EGYPTIAN MEASURES

The unit of volume or capacity, used especially in measuring grain, was the hekat, which can be determined as 292.24 cubic inches, or a little more than half a peck. This was divided into 320 parts called ro, but the Egyptians also used as fractions of a hekat the fractions whose denominators are powers of 2 down to $1/undefined$, $1/undefined$ of a hekat being 5 ro. This series of fractions was peculiarly adapted to multiplication by doubling or halving. They were written in a special notation and have been called “Horus eye” fractions (see Bibliography under Möller, 1911).

Besides using the “Horus eye” notation for parts of a hekat, the Egyptians had special hieratic signs for the numbers from 5 to 10 when used to express hekat. These signs seem to be ligatures of dots, the sign for 10 being a long vertical stroke, representing perhaps ten dots one above another. The Egyptians had also a peculiar way of writing an expression for a large quantity of grain (but, so far as I know,