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THE POPULAR SCIENCE MONTHLY. 



and Calypso, and the floating island of Eolus. A little to the north of 

 the Pillars of Hercules was the entrance to the infernal regions ; and 

 far out in the Western Ocean, beyond the limits of the known earth, 

 was the happy region called Elysium, a land of perpetual summer, 

 where a gentle zephyr constantly blew, where tempests were unknown, 

 and where the spirits of those whose lives had been approved by the 

 gods dwelt in perpetual felicity. Here, also, were the gardens of the 

 Hesperides, with their golden apples guarded by the singing nymphs, 

 who dwelt on the river Oceanus, which was in the extreme west, and 

 the position of which was constantly shifted as geographical knowl- 

 edge increased. 



When the idea became firmly fixed in the mind of the learned that 

 the earth was a sphere, it naturally followed among an artistic people 

 like the Greeks that some attempt would be made to give a physical 



Fig. 4.— Ptolemt's Map, a. h, 150. 



representation of it, and accordingly we are told that Crates (b. c. 326) 

 constructed a globe of the inhabited part of the earth, from the Arctic 

 to the Tropic, in the form of a half-circle. The zone about the tropics 

 he represented as an uninhabitable portion, entirely covered by water 

 (a belief which existed for a long time afterward), and the southern 

 half beyond as that of an unknown but inhabited region. Dicearchus 

 the Messinian (b. c. 296), a very accomplished man, and the writer of 

 several geographical works, which are lost, constructed a map of the 

 world in an oval form, which appears to have been highly estimated, 

 and to have been the model upon which subsequent maps were made. 

 It is inferable from passages in the classic writers that the maps in use 

 represented the unknown parts of the world, in conformity to the ideas 

 deeply implanted in the popular mind by the poems of Homer and 



