Hand (unit) radix numbering system, where a hand is four inches. The hand, sometimes also called a handbreadth or handsbreadth, is an anthropic unit, originally based on the breadth of a male human hand, either with or without the thumb, or on the height of a clenched fist. On surviving Ancient Egyptian cubit-rods, the royal cubit is divided into seven palms of four digits or fingers each. Five digits are equal to a hand, with thumb; and six to a closed fist. The royal cubit measured approximately 525 mm, so the length of the ancient Egyptian hand was about 94 mm. In
Domestication of the horse had a variety of other functions. However, through studies of microscopic wear, it has been established that many of the bone tools at Botai were used to smooth rawhide thongs, and rawhide thongs might have been used to manufacture of rawhide cords and ropes, useful for horse tack. Similar bone thong-smoothers are known from many other steppe settlements, but it cannot be known how the thongs were used. The oldest artifacts clearly identified as horse tack—bits, bridles, cheekpieces, or any other kind of horse gear—are the antler disk-shaped cheekpieces associated with the invention of the chariot, at the Sintashta-Petrovka sites.