266 Penjield — Use of the Stereograjphic Projection for 



To sail from the English Channel to the Gulf of Mexico ; 

 the great circle track (EH.) is from E to a, 10°, and ( W.H.) 

 from a' to the southern end of Florida, 52°. Such are our 

 imperfect ideas concerning a sphere and geographical relations, 

 as derived from ordinary maps, that probably few imagine that 

 in sailing the shortest distance from the English Channel to 

 the Gulf of Mexico the course on leaving the Channel would 

 be nearly due west, in fact a little north of west, as shown by 

 figure 14. 



From the English Channel to the Strait of Magellan ; the 

 track would be {EH.) from E to b, 27°, and ( W.H^) from b' to 

 b", 54°. The same great circle, if continued, would carry to 

 Cape Horn. To proceed to the Strait of Magellan another 

 track would be taken from b", as shown in figure 11, page 260. 



From Northern Luzon, Philippine Islands, to San Francisco; 

 the track is (E.H) from L to c, 40°, and (W.H.) from g' to 

 San Francisco, 57°. The course of this great circle, skirting 

 close to Japan and running not far from the Aleutian Islands, 

 is different from what most people would expect from being 

 familiar with seeing the places on a Mercator's chart. 



The great circle track from Northern Luzon to the western 

 entrance to the Strait of Magellan is (E.H.) from L to-d, 89°, 

 and ( W.H.) from d' to M, 55°. The track, as shown on the 

 map, leads through the Philippine Islands and Australia, and 

 quite close to the Antarctic Continent. In order to sail from 

 Luzon to the Strait two great circle tracks may be followed, 

 thus : (E.H.) from _Z, keeping north of the Solomon Islands, 

 to *, 47°, and ( W.H.) from V to e" , 4°, then from e" to Jf, 

 100°. 



Lastly, the great circle track from New York to the Cape of 

 Good Hope is ( W.H.) from New York to /, 64°, and (EH.) 

 fromy to the Cape, 50°. Continuing this, great circle track 

 around the world, it leads from the Cape of Good Hope across 

 the Indian Ocean, Australia and New Guinea to f in the 

 Pacific Ocean, and from f across the Pacific Ocean and the 

 northern United States to New York. One has but to try to 

 trace some great circle tracks on a sphere to appreciate how 

 difficult it is to follow them exactly, while with a map, such 

 as shown in figure 14, and a protractor they may be followed 

 with the greatest ease. 



It appears worth while to call attention to an erroneous idea 

 concerning geography which most people brought up in the 

 eastern part of the United States seem to have acquired during 

 childhood, namely, that if it were possible to pass through the 

 center of the earth and come out on the opposite side they 

 would find themselves in China. As shown by figure 14 the 



