And, in fact, if you build a 96-sided polygon and roll it on a flat surface, it will indeed roll along reasonably well. That observation leads easily into the next chapter, on wheels and rollers. Long before the advent of the wheel, people rolled their heavy burdens on logs. The celebrated wheel, he writes, wasn't much use until ball bearings were invented. The Romans, for instance, used chariots only for short distances and special occasions, because the crude bearings they used on axles quickly wore out.
Later chapters stray further from the circle.
From the difficulties of inventing the clock and the development of our understanding of the universe, conics, and sine waves, to the discovery of neutrinos, Zebrowski explains the major advances of physics and math simply and understandably, eventually leaving the circle behind. The same book with a different name, minus the first chapter or two, could easily be mistaken for a review of the math you should have learned in high school. That Is . Nowadays most people take the number for granted. It also serves as the boundary between positive and negative integers.