Most of the bridge-heads were constructed by the Russians. A few, generally small ones, were made by the Germans; and some were captured by them, and the defences afterwards elaborated. In this last-named case, they proved a decided annoyance, if not danger, to the Russians: and, about this time, we had orders to destroy, or recapture, a number of them. Most of these were situated on the rivers Vistula, Warta, Pilica and Bzura. The numerous tributaries of these great streams had many fords: bridge-heads were, therefore, useless on brooks and rivulets, as they could be easily turned. The most important works of this class were on the two first-mentioned rivers; and detachments were generally sent out to make simultaneous attacks on a number of them, as this method greatly interfered with, if it did not entirely stop, the enemy sending supporting parties to any one point of the offensive line. On the 27th of the month a number of detachments went out at night to destroy as many of the enemy's posts as possible. These parties, in our district, each consisted of a battalion at reduced strength (600 or 700 men), and about fifty sappers with hand charges of explosives. We had been moved out the previous day, and destroyed a number of temporary bridges for infantry on a stream the name of which did not transpire. We were directed, when retiring, to break the ice behind us: for the streams were all frozen over, though the larger rivers were not, having only a fringe of ice on either bank. The real objective of our expedition was three bridge-heads on the Warta protecting three bridges constructed for the passage of infantry, cavalry and artillery. These bridges were known to be not much in use at the time; but they were likely to greatly benefit the enemy later on. Though some snow had fallen during the day the night was clear and bright, and there was more moonlight than we wanted; but the Germans were evidently off their guard. The plank-bridges on the brooks had not even been watched by a few videttes; and nothing seemed to show that they knew we had been engaged in tearing them down. There was an outpost near the first bridge-head on the Warta, beyond the village of Nishkinova, and half a section was sent to try and get between it and the bridge. The enemy must have taken this party for one of their own patrols, for they took no notice of it.