Leaving “A” Company (Petch) in close support in Cite des Garennes we went out to Red Mill while the attack took place, and the following day, the 19th, the Lincolnshires sent us down 24 prisoners to guard.  Their raid had been a great success, they had cleared the slag-heap and the machine buildings and killed many Boche as well as taken prisoners.  As a result of this the Lincolnshires were able to move into Boot and Brick for their outpost line, and here on the 20th we relieved them.  Twice during the relief the S.O.S.  Signal was fired by our posts in the front line on account of suspected counter-attacks, but our artillery replied so promptly and so efficiently that nothing materialized.

Our second night in the line was disastrous.  During this fighting round Lens, any progress made was the result of minor operations, raids and even patrol fights, and there was seldom a large scale battle.  It was naturally difficult to keep all units informed of the latest progress, and this difficulty was particularly great in our case, when trying to maintain liaison with the Canadians.  The Souchez river was the boundary between the two corps, and made it impossible for us to visit their front line troops.  We had therefore to rely on Division and Corps headquarters keeping each other posted as to the latest progress, and on more than one occasion this liaison broke down, and we suffered very heavily.

At dusk on the 21st we received a message, and at once warned all ranks, that the Special Brigade R.E. were going to carry out a gas bombardment of the mine buildings of Fosse 3.  Projectors would be fired by a Company operating with the Canadian Corps, from whose front the buildings could be best attacked.  The wind was satisfactory, and the buildings were at least 150 yards away from our nearest trenches, so there seemed no need of any special precautions.  “C” Company, occupying Boot and Brick trenches, heard the familiar explosion as the projectors went off, and waited to hear them fall in the buildings.  Instead, they fell in our trenches, several hundred of them; in a few seconds, and before any warning could be shouted, the trenches were full of phosgene, the deadliest of all gasses.  Officers and men worked hard to rouse those resting, and, in particular, 2nd Lieut.  Banwell taking no heed for his own safety, went everywhere, rousing, rescuing and helping the badly gassed.  But it was too late, and all through the night and next morning casualties were being carried out to Lievin and down the line. 2nd Lieuts.  Craggs and Macbeth both went to England, and, almost the last to leave the slag-heap, 2nd Lieut.  Banwell.  His great strength had enabled him to survive longer than the others, but no constitution could stand all that phosgene, and during the morning he suddenly fainted, and had to be carried down.  By the time he reached Lievin he was almost dead, and the Doctors held out no hope of his recovery.  However, fed on oxygen and champagne he lasted a week,