Footnote 9
Part I, §7.  As the 360 degrees answer to 24 hours of time, 15° answer to an hour, and 5° to twenty minutes, or a Mile-way, as it is the average time for walking a mile.  So also 1° answers to 4 minutes of time.  See the two outermost circles in fig. 1, and the divisions of the `border' in fig. 2.