Passus

Passus (from pando), a measure of length, which consisted of five Roman feet. (Col. 5.1; Vitr. 10.14.) [MENSURA] The passus was not the single step (gradus), but the double step; or, more exactly, it was not the distance from heel to heel, when the feet were at their utmost ordinary extension, but the distance from the point which the heel leaves to that in which it is set down. The mille passuum, or thousand paces, was the common name of the Roman mile. [MILLIARE] In connecting the Greek and Roman measures, the word passus was sometimes applied to the extension of the arms,--that> is, the Greek ὀργυιά, which, however, differed from the true passus by half a foot; and, conversely, the gradus was called by Greek writers βῆμα, or τὸ βῆμα τὸ ἁπλοῦν, and the passus τὸ βῆμα τὸ διπλοῦν.

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