This was but part of the destruction proposed. Zebek-Dorchi had it in view to pillage and destroy all the Russian towns, churches, and buildings of every kind within the surrounding district, with outrage and death to their inhabitants,--a frightful scheme, which was providentially checked. The day of flight had been selected, as has been said, in the worst season of the year, in order that the tribes west of the Volga might be able to cross its surface on a thick bridge of ice. Yet for some reason--possibly because of the weakness of the ice--the western Kalmucks failed to join their eastern brethren, and fully one hundred thousand of the Tartars were left behind. It was this that saved the Russian towns, it being feared by the leaders that such a vengeance would be repaid upon their brethren left to Russian reprisal. These western Kalmucks little guessed what horrors they were escaping by being prevented from joining in the flight. The migrating horde was not less than six hundred thousand strong, while a vast number of horses, camels, cattle, goats, and sheep added to the multitude of living forms. The march was a forced one. Every day gained was of prime importance, for it was well known that Russian armies would soon be in hot pursuit, while the tribes on their line of march, hereditary foes of the Kalmucks, would gather from all sides to oppose their passage as the news of the flight reached their ears. The river Jaik, three hundred miles away, must be reached before a day's rest could be had. The weather was not severely cold, and the journey might have been accomplished with little distress but for the forced pace. As it was, the cattle suffered greatly, the sheep died in multitudes, milk began to fail, and only the great number of camels saved the children and the infirm. The first of the subjects of Russia with whom the Kalmucks came into collision were the Cossacks of the Jaik. At this season most of these were absent at the fisheries on the Caspian, and the others fled in crowds to the fortress of Koulagina, which was quickly summoned to surrender by the Kalmuck khan. The Russian commandant, numerous as were his foes, refused, knowing that they must soon resume their flight. He had not long to wait. On the fifth day of the siege, from the walls of the fort a number of Tartar couriers, mounted on the swift Bactrian camels, were seen to cross the plains and ride into the Kalmuck camp at their highest speed.