A marked characteristic of the Lens sector was the frequent and heavy shelling with mustard gas which the enemy poured into Lièvin. On the night of the 26th/27th of May between four and five thousand shells are estimated to have fallen in the town, followed by some three thousand more the next night. Several times in July Lièvin was heavily shelled, chiefly with mustard gas. The men of the 92nd Field Artillery Brigade then began to suffer rather badly from the effects of the gas, although most of them remained at duty. In a heavy bombardment on the 29th of July Major P. Belcher, commanding C/92 Battery, was mortally wounded. [Illustration: LIÈVIN] Meanwhile, on other parts of the front, battles of decisive importance had been fought. Except during the first week of October the 20th Division came hardly at all into any large operations after the retreat in March, but by the end of August the battle area had spread to within a few miles of the Divisional front, and even by the last week in July raids were made in the Lens and Avion sectors with the definite object of assisting operations in other parts of the line. The rôle of the Allied armies up to the middle of July was to preserve the front unbroken until fresh reinforcements and the increasing strength of the American army should make it possible once more to resume the offensive. During this period the Germans continued to seek a decision by delivering attacks in great strength on various parts of the southern battle front. The first of these attacks was unexpectedly launched on the 27th of May west of Rheims and across the Chemin des Dames, involving not only the French but also several British divisions which had been sent to that area to rest. The German forces penetrated to the Marne, where after intense fighting they were held on the 6th of June. Hardly had the offensive on this front been checked when on the 7th of June the Germans attacked the French between Noyon and Montdidier, and forced them to withdraw. On the 15th of July the Germans made a final effort to break through, this time east and south-west of Rheims. After making some progress at first this attack was soon held at all points, and definitely failed. Three days later, on the 18th of July, Marshal Foch delivered the successful counter-attack between Château Thierry and Soissons which so dramatically marked the turn of the tide. Thenceforward the history of the war is an unbroken record of Allied successes.[19] To assist the operations in the south by obtaining identifications and killing as many of the enemy as possible, raids were carried out on the night of the 22nd-23rd of July by a company of the 11th K.R.R.C. in the Avion sector, and by all three battalions of the 61st Brigade opposite Lens, one company of the 12th King’s on the right, two platoons of the 7th D.C.L.I. in the centre, and one platoon of the 7th Somerset L.I. on the left.