One of the measuring standards mentioned by Elsner, who refers to Edward William Lane, »Sitten und Gebräuche der heutigen Egypter« (2nd ed., Leipzig, 1856 [transl. of »An account of the manners and customs of the modern Egyptians,,,« (London, 1836)]), explaining that "the numerous measures for folk instruments, described in the relevant literature, are derived from body measurements"; NB: Obviously this renders a general conversion into exact measurements (cm, &c.) rather difficult, if not impossible.