SCIENCE OF THE ROMAN PERIOD 



definite notion as to the shape of this island. This 

 shape Strabo likens to a military cloak. The compari- 

 son does not seem peculiarly apt when we are told 

 presently that the length of the habitable earth is more 

 than twice its breadth. This idea, Strabo assures us, 

 accords with the most accurate observations "both 

 ancient and modern." These observations seemed to 

 show that it is not possible to live in the region close 

 to the equator, and that, on the other hand, the cold 

 temperature sharply limits the habitability of the globe 

 towards the north. All the civilization of antiquity 

 clustered about the Mediterranean, or extended off 

 towards the east at about the same latitude. Hence 

 geographers came to think of the habitable globe as 

 having the somewhat lenticular shape which a crude 

 map of these regions suggests. We have already had 

 occasion to see that at an earlier day Anaxagoras 

 was perhaps influenced in his conception of the shape 

 of the earth by this idea, and the constant refer- 

 ences of Strabo impress upon us the thought that this 

 long, relatively narrow area of the earth's surface 

 is the only one which can be conceived of as hab- 

 itable. 



Strabo had much to tell us concerning zones, which, 

 following Posidonius, he believes to have been first 

 described by Parmenides. We may note, however, 

 that other traditions assert that both Thales and Py- 

 thagoras had divided the earth into zones. The num- 

 ber of zones accepted by Strabo is five, and he criticises 

 Polybius for making the number six. The five zones 

 accepted by Strabo are as follows: the uninhabitable 

 torrid zone lying in the region of the equator ; a zone on 



261 



