208 



PHYSIOGRAPHY 



pole on the earth's surface are meridians. All meridians come 

 together at each pole. 



A few meridians and parallels are shown in Fig. 203, which 

 shows the earth in two positions. The left-hand part of the figure 



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Fig. 203. Parallels and meridians. 



shows the half of each parallel represented, and the whole of each 

 meridian. The right-hand part shows the relation of parallels 

 to the North Pole. The distance between the equator and either 

 pole is divided into 90 parts, called degrees (written 90). Each 

 degree is divided into 60 parts, called minutes (written 60'). Each 

 minute is divided into 60 parts, called seconds (written 60"). 

 Distance north or south of the equator may therefore be deter- 

 mined from a globe or map by means of parallels. 



Distance north or south of the equator is called latitude. North 

 latitude is north of the equator, and south latitude is south of it. 

 The degrees, minutes, etc., are numbered from the equator toward 

 the poles. The latitude of the equator is 0. Latitude 1 N. is 

 one degree north of the equator, and latitude 90 N. is at the North 

 Pole. Latitude 1 S. is one degree south of the equator, and lati- 

 tude 90 S. is at the South Pole. If the latitude of a place is 40 

 40' 40" N., its distance and its direction from the equator are accur- 

 ately known; but its position on the parallel of 40 40' 40" is not 

 known, for that parallel runs quite around the earth. 



Longitude. Position on a parallel is indicated by means of the 

 meridians. The number of possible meridians is very great, but as 

 in the case of parallels, only a few are commonly shown on maps. 

 One meridian, that passing through Greenwich, England, was long 



