As regards the age to which the writer belonged: it is first of all evident that he wrote after the times of Augustus, since in § 23 mention is made of the Roman Emperors. That he was older, however, than +Ptolemy+ the Geographer, is proved by his geography, which knows nothing of India beyond the Ganges except the traditional account current from the days of Eratosthenês to those of Pliny, while it is evident that Ptolemy possessed much more accurate information regarding these parts. It confirms this view that while our author calls the island of Ceylon +Palaisimoundou+, Ptolemy calls it by the name subsequently given to it—+Salikê+. Again, from § 19, it is evident that he wrote before the kingdom of the Nubathæans was abolished by the Romans. Moreover Pliny (VI. xxvi. 101), in proceeding to describe the navigation to the marts of India by the direct route across the ocean with the wind called Hippalos, writes to this effect:—“And for a long time this was the mode of navigation, until a merchant discovered a compendious route whereby India was brought so near that to trade thither became very lucrative. For, every year a fleet is despatched, carrying on board companies of archers, since the Indian seas are much infested by pirates. Nor will a description of the whole voyage from Egypt tire the reader, since now for the first time correct information regarding it has been made public.” Compare with this the statement of the _Periplûs_ in § 57, and it will be apparent that while this route to India had only just come into use in the time of Pliny, it had been for some time in use in the days of our author. Now, as +Pliny+ died in 79 A.D., and had completed his work two years previously, it may be inferred that he had written the 6th book of his _Natural History_ before our author wrote his work. A still more definite indication of his date is furnished in § 5, where +Zoskalês+ is mentioned as reigning in his times over the Auxumitae. Now in a list of the early kings of Abyssinia the name of +Za-Hakale+ occurs, who must have reigned from 77 to 89 A.D. This +Za-Hakale+ is doubtless the +Zoskalês+ of the _Periplûs_, and was the contemporary of the emperors Vespasian, Titus, and Domitian. We conclude, therefore, that the _Periplûs_ was written a little after the death of Pliny, between the years A.D. 80-89.