text: The same people who invented the wheel five or six thousand years ago (the Mesopotamians) also fancied the number sixty, basing their entire number system on it. No one seems to know exactly why--it might even have been related to trade: for commercial purposes, it's helpful to use a number that has many factors, and sixty has twelve of them, more than any other manageable number.... Whatever the reason, the Babylonians picked the system up and passed it on to the Egyptians, who used it to divide the circle into 360 degrees (6 x 60) and who also gave us the symbol for degrees. The Egyptians divided spheres into 360 degrees as well, assigning the first latitude and longitude lines to the earth. This ancient system for dividing the circle has persisted to the present. Each degree of the circle is divided into 60 minutes (60') and each minute into 60 seconds (60").\n\nFor more information about the origin of the system for dividing a circle into 360 degrees see also:\n\nBynum, W. F. Dictionary of the History of Science, Princeton University Press, Princeton, N.J., 1981. (R 509 B99) \n"Circle -- History", Encyclopedia Americana, (1992) vol. 6, p.733. \nGettings, Fred. Secret Symbolism in Occult Art. Harmony Books, New York, 1987 (OV 133 G33)