INFLUENCE OF THE ROMAN EMPIRE. 555 



course of the Romans with China and India, since it is highly 

 probable that the knowledge of the Greek sphere and zodiac, 

 as well as that of the astrological planetary week, was not 

 generally diffused until the first century of our era, and that 

 it was then effected by means of this intercourse between the 

 two countries.* The great Indian mathematicians, Waraha- 

 mihira, Brahmagupta, and perhaps even Aryabhatta, lived at 

 a more recent period than that under consideration ;f but the 

 elements of knowledge, either discovered by Indian nations, 

 frequently in different and wholly independent directions, or 

 existing amongst these ancient civilised races from primitive 

 ages, may have penetrated into the west even before the time 

 of Diophantus, by means of the extended commercial relations 

 existing between the Ptolemies and the Caesars. I will not 

 here attempt to determine what is due to each individual race 

 and epoch, my object being merely to indicate the different 

 channels by which an interchange of ideas has been effected. 



The strongest evidence of the multiplicity of means, and the 

 extent of the advance that had been made in general inter- 

 course, is testified by the colossal works of Strabo and Ptole- 

 my. The gifted geographer of Amasea does not possess the 

 numerical accuracy of Hipparchus, or the mathematical and 

 geographical information of Ptolemy; but his work surpasses 

 all other geographical labours of antiquity by the diversity of 

 the subjects, and the grandeur of the composition. Strabo, 

 as he takes pleasure in informing us, had seen with his owe 

 eyes a considerable portion of the Roman empire, " from 

 Armenia to the Tyrrhenian coasts, and from the Euxine to the 

 borders of Ethiopia." After he had completed the historical 

 work of Polybius by the addition of forty-three books, he had 

 the courage, in his eighty-third year,| to begin his work on 



* See Letronne, in the Observations critiques et archeologiques sur 

 les representations zodiacales de TAntiquite, 1824, p. 99, as well as his 

 later work, Sur I'origine grecque des Zodiaques pretendus egyptiens, 

 1837, p. 27. 



t The sound enquirer, Colebrooke, places Warahamihira in the fifth, 

 Brahmagupta at the end of the sixth century, and Aryabhatta rather 

 indefinitely between the years 200 and 400 of our era. (Compare 

 Holt/.mann, Ueber den griechischen Ursprung des indischen Thier- 

 krei#es, 1841, 8. 23.) 



J On the reasons on which we base our assertion of the exceedingly 

 late commencement of Strabo's work, see Groskurd's German transla- 

 tion, th. i. 1831, s. xvii. 



