Hew a mortar three feet (_tripodīn_) in diameter, and a pestle three cubits (_tripichtēn_), and an axletree seven feet (_heptapodīn_) ... and hew a wheel of three spans (_trispithamon_) for the plough-carriage of ten palms (_dekadōro_) length. Besides the original division of the foot into 16 finger-breadths or digits, there arose an alternative division into 12 thumb-breadths or inches. So for the Roman foot, of shorter standard than the Egyptian or Olympic foot from which it was derived— Pes habet palmos iv, uncias xij, digitos xvi, Palmus habet digitos iv, uncias iij. It may be said that with the foot originated the sexdecimal system, as with the span the duodecimal system. But the foot had as many inches, twelve, as the span had of digits; and this division was the same in other feet or spans not differing much from the Olympic standard. The popularity of the foot, its general adoption for the common purposes of life, are due to its being divided into either 12 inches or 16 digits, the familiar thumb-breadths and finger-breadths. Every popular system meeting the convenience and the ways of thought of men and women, must have its measures of length approximately coinciding with the familiar units of limb-lengths, and it must be divided sexdecimally or duodecimally to enable people, men, women and children, to calculate mentally in the everyday business of life. The octonary or semi-sexdecimal mode of division seen in our Pint-Gallon-Bushel series is also very convenient, especially for measures of capacity and for land-measures, admitting extensive halving and quartering with subordinate units at each division. Duodecimal division having the convenience of thirding is convenient for the coinage series. A combination of the score and dozen series, as in our money-pound of 20 × 12 pence, combines the advantages of extensive halving and thirding. But never has man taken to a decimal series of weights and measures; he may use them on compulsion, and then will evade them whenever he can. He has ten fingers, whence decimal numeration from the earliest times; but he has always rejected decimal measures.[1] Footnote 1: Even in numeration he often prefers to count by the score. The Welshman says _dega-dugain_ (10 and 2-score), the Breton _quarante et dix_, other Frenchmen _quatre-vingt-dix_ (4 score and 10)