Earth's circumference mile in the seventeenth century and the metre in the eighteenth. Earth's polar circumference is almost exactly 40,000 km because the metre was originally calibrated on this measurement (1/10-millionth of the distance between the poles and the equator), which is almost exactly 21,600 nautical miles (being defined as one minute of a degree – i.e. 360 multiplied by 60). It has been described as "the single most important measurement" of the Earth, assuming the Earth to be a sphere (the Earth is an technically an ellipsoid, albeit with just 0.3% flattening). Earth's circumference lines are the foundation of the coordinate
USS Wissahickon (SP-852) at East Boston, Massachusetts, for the rest of World War I and into January 1919. Apparently sometime between September and November 1918, and definitely by 1 January 1919, her name was changed from USS "SP-852" to USS "Wissahickon" (SP-852). Late in January 1919, "Wissahickon" moved to Camden, Maine. She was stricken from the Navy List on 10 February 1919 and was decommissioned at Camden on 12 February 1919. On 15 February 1919, she was ordered returned to Mrs. Henry. USS Wissahickon (SP-852) The second USS "Wissahickon" (SP-852), which also served as USS "SP-852", was a United States Navy patrol vessel