Towards the end of January the Russians began to take the offensive on the wings. At this time, you must remember, the new forces which the Allies in the West had raised were not yet ready to take the field. The "thin line of steel and valour" in Artois and Flanders was only just holding its own, and it was feared that if the Germans brought troops from the East they would be able to break through the Allied line and reach the Channel ports. The Grand Duke Nicholas was, therefore, requested to attack von Hindenburg, and prevent him from releasing troops for service in the West. Earlier in the war he had sacrificed large numbers of his men in East Prussia to give his Western Allies a breathing space. Now, although his forces were very weak in guns, rifles, and ammunition, he showed the same high courage and chivalry. He knew that, if he pushed forward into the sacred land of East Prussia, von Hindenburg would hasten to engage him, and that if he threatened Hungary, the great granary of the Central Powers, the enemy would be bound to oppose him. The Grand Duke Nicholas was well aware that he could not hope for conquest. All that he could do would be to worry the enemy and prevent him from sending troops to the West. [Illustration: The Russians retaking a Trench before Bolimov. (_By permission of The Illustrated London News._) The following account of the incident pictured above was given by a Russian soldier:--"They did not stay long when we came down on them with our bayonets. Our artillery had dropped many shells right in the trench before we got there. The machine guns played on us until the last minute, and we paused to fire at the gunners. The few Germans who were left tried to drag the guns away with them, but our men took them away from them."] In order to provide a sufficient force for these attacks, the Russians had to draw off men and guns from their centre. Von Hindenburg knew this, and he therefore determined to make another effort to capture Warsaw by a frontal attack. The fifty-sixth birthday of the Kaiser was drawing near, and what better present could be made to him than the great Polish capital? You will remember that at this time the Russians were lying along the right bank of the Bzura and its tributary the Rawka. Look at the map on the next page and find the town of Bolimov, on the western bank of the Rawka. It is about forty miles from Warsaw, and is connected with it by a fairly good road. In front of Bolimov there are rolling downs and belts of wood. You will notice that the Russian lines cross the Rawka south of Bolimov. On the last day of January von Mackensen, who had brought up large numbers of heavy guns all along the left bank of the Rawka, began a terrific bombardment of the Russian lines. This was done to puzzle the Russians and make them uncertain as to where the infantry attack was to be made. The Germans proposed to advance on a line of seven miles between Bolimov and the Bzura.