Sometimes, too, the places where the engines were set up were protected by wooden bulwarks, which, together with the frame-work itself of the engines, were covered with raw hides, to prevent their being set on fire by the enemy. The number of raw hides required for this purpose was immense, and to obtain them the Monguls slaughtered vast herds of horses and cattle which they plundered from the enemy. In order to embarrass the enemy in respect to ammunition for their engines, the people of a town, when they heard that the Monguls were coming, used to turn out sometimes in mass, several days before, and gather up all the stones they could find, and throw them into the river, or otherwise put them out of the way. In some cases, the towns that were threatened, as has already been said, did not attempt to resist, but submitted at once, and cast themselves on the mercy of the conqueror. In such cases the Mongul generals usually spared the lives of the inhabitants, though they plundered their property. It sometimes happened, too, that after attempting to defend themselves for some time, the garrison would become discouraged, and then would attempt to make some terms or conditions with the conqueror before they surrendered. In these cases, however, the terms which the Monguls insisted upon were often so hard that, rather than yield to them, the garrison would go on fighting to the end. In one instance there lived in a town that was to be assailed a certain sheikh, or prince, named Kubru, who was a man of very exalted character, as well as of high distinction. The Mongul general whom Genghis Khan had commissioned to take the town was his third son, Oktay. Oktay had heard of the fame of the sheikh, and had conceived a very high respect for him. So he sent a herald to the wall with a passport for the sheikh, and for ten other persons such as he should choose, giving him free permission to leave the town and go wherever he pleased. But the sheikh declined the offer. Then Oktay sent in another passport, with permission to the sheikh to take a thousand men with him. But he still refused. He could not accept Oktay's bounty, he said, unless it were extended to all the Mohammedans in the town. He was obliged to take his lot with the rest, for he was bound to his people by ties too strong to be easily sundered. So the siege went on, and at the end of it, when the town was carried, the sheikh was slain with the rest in the streets, where he stood his ground to the last, fighting like a lion. All the Mohammedan chieftains, however, did not possess so noble a spirit as this. One chieftain, when he found that the Monguls were coming, caused himself to be let down with ropes from the wall in the night, and so made his escape, leaving the town and the garrison to their fate.