Page 143

(Con’t)

…determining geographical localities than this, and while the map of the world has undergone wonderful changes in that time, geographers have always retained these lines. We know them now as the “parallels” of latitude, and the “meridians” of longitude.

Latitude is distance N or S. of the Equator. The Equator is latitude 0 [zero]. Longitude is distance E or W of any meridian that may be determined upon as a place to begin, counting, generally that meridian that passes through the Royal Observatory at Greenwich, Eng. Because that observatory was founded by Charles II for the purpose of determining astronomical data for the use of navigators.

A line drawn around a globe is necessarily a circle, and, a, circle has 360° (° "degrees"). Consequently, there are 360° of both long. and lat. – That is, if a man could walk around the globe on the equator, he would cross 360 meridians of long., one degree (1°) apart, and, the circumference of the earth being about 25,000 miles at the equator, each °  [decree] would be a trifle over 69 land miles from the next. Considering the earth as a perfect spear, there would be the same distance between each degree line of latitude. Suppose this man to begin his damp and stormy walk at that spot where the Greenwich meridian, crossed the equator, he would begin at lat. 0, long. 0, which is a spot in the Gulf of Guinea. For every 69 M he walked to the W'd., he would change his long. 1°; at the end of the second 69 M, for example, he would be in lat.0, longitude 2 west. Exactly halfway around the earth, he would be at long. 180. As the long. is counted both ways, E and W for 0 to 180, this is the highest number he would reach, the count from that point decreasing with every 69 M. and being counted E instead of W; – thus the next one degree would be 179° E long: - the next degree would be 178° E long., and so on to long 0 [zero] again at the…

(Con’t)