Latitude exact relationship of parallels and meridians with horizontal and vertical: both are complicated curves. On the sphere the normal passes through the centre and the latitude () is therefore equal to the angle subtended at the centre by the meridian arc from the equator to the point concerned. If the meridian distance is denoted by then where denotes the mean radius of the Earth. is equal to . No higher accuracy is appropriate for since higher-precision results necessitate an ellipsoid model. With this value for the meridian length of 1 degree of latitude on the sphere is (60.0 nautical miles).
How Many Miles to Babylon? good and your spurs be bright. How mony men have ye? Mae nor ye daur come and see.</poem> Various places have replaced Babylon in the rhyme, including London town, Barberry and Berry Bright. The rhyme was not recorded until the nineteenth century, but the reference to Cantelon in the Scottish version has led some to conclude that it refers to Caledon in the time of the Crusades. Babylon may be a corruption of 'Babyland', but the city was a common allusion particularly in seventeenth-century England and 'Can I get there by candlelight?' was a common saying in the sixteenth century.