On the morning of April 10 the two brigades which had crossed the river were in very evil case, having sustained heavy losses. They were concentrated about Le Mortier. The 74th Brigade was in position south of Croix du Bac in touch on the right with the 150th Yorkshire Territorials. All day the enemy were pushing west and north, but meeting a strong resistance from the British who had an excellent trench, the Steenwerck switch, to help them. Some ground was lost, but much of it was regained in the evening by a spirited counter-attack of the 14th and 10/11th Highland Light Infantry, the 2nd Scots Fusiliers, and the 21st Middlesex, which advanced over 600 yards. The pressure was great and unceasing, however, so that the morning of April 11 found the line farther back again. The two brigades were reduced to about 1000 men, who were concentrated at Strazeele, while the 92nd and 93rd Brigades of the Thirty-first Division came up in their place. A brave counter-attack by the 93rd Brigade at Le Verrier gained its objective, but created a dangerous gap between it and the 92nd Brigade on its right, which was filled, however, by the 11th East Yorkshires. On the 12th the remains of all three brigades were strung out to cover Strazeele and Hazebrouck from the east and south-east, but next day they were relieved by the welcome appearance of the First Australian Division, whose advent will afterwards be explained. It had been a very desperate term of service, in which for three days the sappers of the 224th, 229th, and 231st Field Companies Royal Engineers had to fight as hard as the infantry. The Fortieth, like the other divisions described, were driven back, but only as the buffer is driven back, {238} with the ultimate result of stopping the force which drove it. They were much aided by the guns of the Fifty-seventh Division under General Wray. The losses of the division were 185 officers and 4307 other ranks. When one reflects that the losses on the Somme three weeks before had been equally heavy, one can but marvel. We shall now follow the fortunes of the Thirty-fourth Division (Nicholson), which was on the immediate left of the Fortieth, covering a sector of 8000 yards, including the town of Armentières. On the north, near Frelinghien, it joined the right of the Twenty-fifth Division. On the night of April 7 the enemy fired an enormous number, 30,000 or 40,000, gas-shells into Armentières, and soaked it to such an extent with mephitic vapours that it became uninhabitable. Otherwise there was no warning of an impending attack, which came indeed as a surprise to all the forces engaged.