SCIENCE IN THE ANCIENT WORLD 57 



practically no method then by which longitudes could 

 be determined with any accuracy. Nevertheless, put 

 together from information brought by traders and 

 explorers, Ptolemy's maps of the known world, ex- 

 tending from the shores of the Malay peninsula and 

 the coast-line of China to the Straits of Gibraltar and 

 the Fortunate Islands, from Great Britain, the Scandi- 

 navian lands, and the Russian steppes to a vague land 

 of lakes at the head-waters of the Nile, retain their 

 interest. His general treatment of the subject is that 

 of an astronomer rather than a geographer, for he 

 makes no attempt to describe climate, natural pro- 

 ductions or even the aspects which would now be 

 included under physical geography ; nor does he 

 avail himself, to any large extent, of the descriptions 

 and accounts of lands within the Roman Empire which 

 must have been accessible in the military "itineraries." 



Whatever be the cause of the phenomenon, it 

 clear that, even before the decay of Rome as a political 

 power, science, in common with other forms of thought, 

 had come almost to a standstill. No advance in 

 knowledge was being made, and all that was done was 

 in the direction of writing compendiums and com- 

 mentaries, chiefly on the Greek philosophers, and in 

 especial on Aristotle, who came to be regarded as 

 the great authority on all questions of scientific theory t 

 and even of actual fact. 



While Greek learning, receiving no reinforcements, 



lost itself in the capital and the western territories 



The influence f the Roman Empire, it pursued a more 



of Alexandria, fertile course in the lands and cities of 



the Eastern Mediterranean, whence it had received its 



