The Paris inch or pouce is an archaic unit of length that, among other uses, was common for giving the measurement of lenses. The Paris inch could be subdivided into 12 Paris lines (ligne), and 12 Paris inches made a Paris foot. The abbreviations are the same as for other inch and foot units, i.e: for Paris foot a unique prime symbol ( ′ ), for Paris inch a double prime symbol ( ″ ) and for Paris line a triple prime symbol ( ‴ ), The Paris inch is longer than the English inch and the , although the Vienna inch was subdivided with a decimal, not 12 lines.