It is doubtful whether we are to include among these devices the use of military engines. On the one hand, we have several distinct statements by the author of the “Cyrpoasdia,” to the effect that engines were well known to the Persians; on the other, we remark an entire absence from the works of other ancient writers of any notice that they actually employed them, either in their battles or their sieges. The silence of Scripture, of Herodotus, of the inscriptions, of Quintus Curtius, of Arrian, may fairly be regarded as outweighing the unsupported authority of the romance-writer, Xenophon; and though it would be rash to decide that such things as siege-towers, battering rams, and balistce--all of which are found to have been in constant use under the Assyrian and Babylonian monarchies--were wholly discarded by, or unknown to, their successors in the government of Asia, yet a wise criticism will conclude, that they were, at any rate, unfamiliar to the Persians, rarely and sparingly (if at all) employed by them, other methods of accomplishing the ends whereto they served having more approved themselves to this ingenious people. In ordinary sieges it would seem that they trusted to the bank or mound, while sometimes they drove mines under the walls, and sought in this way to effect a breach. Where the place attacked was of great strength, they had recourse in general either to stratagem or to blockade. Occasionally they employed the destructive force of fire, and no doubt they often succeeded by the common method of escalade. On the whole, it must certainly be said that they were successful in their sieges, exhibiting in their conduct of them courage, activity, and considerable fertility of resource.