conduits, which are sometimes carried many miles from the foot of the mountains.  The position of the wells, which were few in number, was known only to the natives; and Artabanus hoped that the Syrian monarch would be afraid to place the lives of his soldiers in such doubtful keeping.  When, however, he found that Antiochus was not to be deterred by any fears of this kind, but was bent on crossing the desert, he had recourse to the barbaric expedients of filling in, or poisoning, the wells along the line of route-which the Syrian prince was likely to follow.  But these steps seem to have been taken too late.  Antiochus, advancing suddenly, caught some of the Parthian troops at their barbarous work, and dispersed them without difficulty.  He then rapidly effected the transit, and, pressing forward, was soon in the enemy’s country, where he occupied the chief city, Hecatompylos.  Up to this point the Parthian monarch had declined an engagement.  No information has come down to us as to his motives; but they may be readily enough conjectured.  To draw an enemy far away from his resources, while retiring upon one’s own; to entangle a numerous host among narrow passes and denies; to decline battle when he offers it, and then to set upon him unawares, has always been the practice of weak mountain races when attacked by a more numerous foe.  It is often good policy in such a case even to yield the capital without a blow, and to retreat into a more difficult situation.  The assailant must follow whithersoever his foe retires, or quit the country, leaving him unsubdued.  Antiochus, aware of this necessity, and rendered confident of success by the evacuation of a situation so strong, and so suitable for the Parthian tactics as Hecatompylos, after giving his army a short rest at the captured capital, set out in pursuit of Artabanus, who had withdrawn his forces towards Hyrcania.  To reach the rich Hyrcanian valleys, he was forced to cross the main chain of the Elburz, which here attains an elevation of 7000 or 8000 feet.  The route which his army had to follow was the channel of a winter-torrent, obstructed with stones and trunks of trees, partly by nature, partly by the efforts of the inhabitants.  The long and difficult ascent was disputed by the enemy the whole way, and something like a pitched battle was fought at the top; but Antiochus persevered, and, though his army must have suffered severely, descended into Hyrcanian and captured several of the towns.  Here our main authority, Polybius, suddenly deserts us, and we can give no further account of the war beyond its general result—­Artabanus and the Parthians remained unsubdued after a struggle which seems to have lasted some years; Artabanus himself displayed great valor; and at length the Syrian monarch thought it best to conclude a peace with him, in which he acknowledged the Parthian independence.  It is probable that he exacted in return a pledge that the Parthian monarch should lend him his assistance