Many of these shells were fired from the Austrian batteries stationed over near Semlin, but presently there also appeared a fleet of river monitors, so heavily armored that no Serbian shell could pierce their sides. These would parade up and down the river channel with impunity, adding their share to the general destruction. Finally, in the beginning of November, 1914, there arrived in Belgrade two big 14-centimeter cannon, sent by the French Government by way of the Adriatic, together with French gunners and 20,000 rounds of ammunition. These were put into position above the city and on November 8, 1914, the French gunners sent their first message over into Hungary. The damage inflicted so impressed the monitors that they did not again venture into range. Moreover, spies, of whom there were probably a number in Belgrade, had doubtless notified the Austrians that measures, were now being taken to mine the river effectively. In fact, many measures for a more effective offensive were being undertaken when the trend of operations in the interior forced the Serbian General Staff to order the evacuation of the capital. It will be remembered that the Serbians had been beaten back from their main line of defense and that a rearrangement of the Serbian forces had thereby become necessary, in order that the line might be shortened. This included the abandonment of Belgrade on November 29, 1914. The order was carried out during the night. But before retiring, the French gunners, who saw that they were going to lose their two big guns, determined to bid the enemy across the river a hearty good-by. In the early morning they fired off their stock of 240 rounds of ammunition and in a little more than half an hour deposited some twelve tons of melinite on the enemy's forts at Bezania, with such terrifying effect that the garrison abandoned it. Thus it came to pass that the two strongholds, having snarled and barked at each other across the dividing waters for nearly five months, were both evacuated at the same time. As will be remembered, the right wing of the Serbian lines, now joined by the garrison of Belgrade, swung back and stretched across the Belgrade-Nish railroad, along the ridges of Varoonitza in the east and Kosmai in the west. The Austrian left, composed of two army corps, immediately covered the ceded territory and, of course, entered Belgrade. Then followed the strong Serbian counterattack against the Austrian center along the Suvobor ridges and the complete demoralization of the Austrian forces from the center south.