on the compositions of yards and perches

Looking to buy a new television, I tried to assay the difference between the German measurement of Zoll and inches across—if there was any and whether that distance mattered if measured diagonally as opposed to on a grid and there was a little more to the story than we expected. An inch (also statutorily three dry barley corn or fifteen poppy seeds across) was traditionally defined as the width of an adult’s thumb, a twelfth of a foot—give or take.
Although a Zoll as a unit has a bit more precision invested in it and is greater than an inch by an exacting but negligible amount—it’s also short for the informal and nebulous length of a “Stück Holz” or a piece of wood and is curiously the width of a Zollstock, one of those collapsible measuring sticks commonly found in Germany, more in use than a tape-measure to assess something’s size in exact terms. Although one will most likely only encounter the unit itself for screen-dimensions, it’s also present in contemporary pants sizes, bullet calibres and nuts and bolts. Twelve inches make a foot and three feet make a yard; five and a half yards make a perch and forty by four perches (also termed one chain by one furlong) make an acre, which was itself defined as the area of land that could be reasonably expected to be ploughed by a yoke (pair) of oxen in the space of a day. Before adopting the metric system in 1871, German conventional weights and measures were even more confusing and incongruent with a Landmeile (Land Mile) ranging in value from twenty-four thousand feet (Füß, itself ranging from nine to eighteen inches) in Bavaria and Württemberg to a thousand metres (three thousand two hundred eight one feet) in Wiesbaden. The above mentioned Zoll usually made one-twelfth part of a foot but in some places it was considered one-tenth.