“What’s the good of Mercator’s North Poles and Equators, Tropics, Zones and Meridian Lines?” asked the bellman in Lewis Carroll’s poem “The Hunting of the Snark”. Meridian lines are:
A) Lines dividing the oceans in two B) Lines used by sailors to set the sails C) Mnemonics used in learning navigation D) Lines of longitude ü
If you draw a great circle around the earth from pole to pole, you have drawn a meridian line. What’s the use of them? Longitude is one of the two quantities that tell sailors their position on the surface of the earth. (The other is latitude.) In early days, longitude could only be estimated. Modern instruments give one’s exact longitude without calculation.
