+28.+ Arsaces expected that Antiochus would come as far as this district (of Media), but that he would not venture to proceed across the adjoining desert with so large a force, if for no other reason, yet from the scarcity of water. For in this tract of country there is no water appearing on the surface, though there are many subterranean channels which have well-shafts sunk to them, at spots in the desert unknown to persons unacquainted with the district. A true account of these channels has been preserved among the natives to the effect that, during the Persian ascendency, they granted the enjoyment of the profits of the land to the inhabitants of some of the waterless districts for five generations, on condition of their bringing fresh water in; and that, there being many large streams flowing down Mount Taurus, these people at infinite toil and expense constructed these underground channels through a long tract of country, in such a way, that the very people who now use the water are ignorant of the sources from which the channels are originally supplied. [Sidenote: Antiochus prepares to cross it: Arsaces orders the wells to be choked.] [Sidenote: Antiochus arrives at Hecatompylos.] When, however, Arsaces saw that Antiochus was determined to attempt to cross the desert, he endeavoured at once to choke up and spoil the wells. But King Antiochus, upon this being reported to him, despatched Nicomedes with a thousand horse; who found that Arsaces had retired with his main army, but came upon some of his cavalry in the act of choking up the shafts which went down into the underground channels. They promptly attacked these men, and, having routed and forced them to fly, returned back again to Antiochus. The king, having thus accomplished the journey across the desert, arrived before the city Hecatompylos, which is situated in the centre of Parthia, and derives its name from the fact that the roads which lead to all the surrounding districts converge there. [Sidenote: Antiochus determines to follow Arsaces into Hyrcania.]