Convert from millimeter to barleycorn

Unit Definition (millimeter)
The millimeter (or millimetre) is one of the most common metric units of distance. One millimeter is exactly one thousandth of a meter. The millimeter is also an engineering standard unit.

Unit Definition (barleycorn)
The Barleycorn is an old English unit of length. The custom of using seeds as units of length or weight is very common in farming societies. In Anglo-Saxon England, where barley was a basic crop, barleycorns played this traditional role. The weight of a barleycorn, later renamed the grain, is the original basis of all English weight systems including the older troy system and the later avoirdupois system. As a length unit, 3 barleycorns were equal to the Saxon ynce (inch). The English foot was actually defined as 12 of these ynces, that is, as 36 barleycorns.