Between 2 and 3 o'clock in the morning a violent bombardment with gas shells was started against a section of our line about two and three-quarters miles long, and divided into four approximately equal parts by the roads from Ypres to St. Julien and Moorslede and the railway from Ypres to Roulers. The supply of gas available must have been great, for it continued to pour southwestward for some hours in great volume, in some places reaching to a height of several feet. Owing to the direction of the wind, also, it swept southward along our line as well as penetrating behind it. The manner in which such an attack develops with a favoring wind cannot better be described than by the reports of its progress brought in on Monday morning by our aerial reconnaissances. One observer who crossed the opposing front in this quarter shortly after dawn reported when he came back that a thick cloud of what looked like smoke outlined the whole of the German trenches. The next observing officer, who arrived some time afterward, stated that to the west and southwest of the German line he could see a broad band of yellow grass and trees which looked as if they had been bleached. A third, who came in later, stated that the whole area behind our line was covered by a mist so thick as to interfere with observation. This attempt to asphyxiate was of course preliminary to an assault against the salient, for which infantry had been massing on the east. It was carried out from three directions, being pushed forward under cover of a heavy bombardment against the northern face from the neighborhood of St. Julien, against the northeast face from Zonnebeke along the Roulers Railway, and against the west direct from the Polygon Wood. On the greater part of the front assailed our troops were able to stand their ground, and to maintain their positions in spite of the poisonous fumes, but in certain sections they were forced to evacuate the trenches, and the German infantry succeeded in getting a footing in our front line near the farm to the north of Wieltje, for some distance astride the Roulers Railway, and to the north and south of the Menin Road on the south of the Bellewaarde Lake. In doing this the enemy lost considerably both from our artillery fire and the rifle fire of the sections of the defense which were able to maintain their position. Counter-attacks were organized during the morning, and by about midday our infantry had succeeded in reoccupying our former line to the north of the railway. By evening there were no Germans west of our original position on the south of the Menin Road, though we had not been able to reoccupy our line in that quarter, nor near Wieltje. The advance of the enemy, however, had been stopped. In the neighborhood of Hill 60 a party of our infantry during the night bombed their way for some forty yards up a trench which the Germans had taken from us, destroyed the enemy's barricade, reconstructed it, and held the trench.