, meaning a tiny stone (from sharp stone), indicates a weight of of a Roman ounce (i.e.) or, by extension, of other measures. Metaphorically, the stone is thought to be sharp and pricking, like a thorn. As a weight or a coin, of an , or of an as; i.e. 1.14 grams As a measure of land, of a ; i.e. about As a measure of time, part of an hour, or minutes. The forms , , and can be found, being also associated with the lines on a draughtboard. See also Roman currency References , Hachette 1934 Coins of ancient Rome Ancient Roman units of measurement Units of mass