Sidereal time means that when a star is directly over one point on the ground, 1 second later the same star will be directly over another point 1000 cubits from the first, westwardly in line with the earth's rotation from the first point. The inventors of the metric system should have looked up the history of Egyptian measurement.
There is a relic of this in shoe sizes; a number 8, for instance, is 11" long, a number 9 is 11-1/3", a number 10 is 11-2/3", the sizes increasing by 1/3 of an inch, i.e. a barleycorn. Some old books, by the way, go even lower than the barleycorn, and give twelve hairsbreadths = 1 poppy-seed; four poppy seeds = 1 barleycorn.