the evening of Tuesday 19 March Lawrence ("purring on the telephone like a damned pussycat") once again refused permission to move up the 20th and 50th Divisions. 21 March The German attack began at 4:40 am on 21 March; Gough, Beddington and other rear echelon officers recorded being awakened at around 5:10 am, when British artillery, hampered by the fog, began to return fire. The Germans had over 8,000 guns and trench mortars. Much of the German bombardment (described by eyewitnesses as "a wall of orange flame" and "a sea of fire") concentrated on British headquarters and communications, while pauses were left in the bombardment of the British front lines to tempt the defenders out of their shelters. Gas was also used, although mustard gas was not used in areas through which German troops were to pass. 19 German divisions assaulted six of Byng's Third Army, while 43 German divisions attacked Fifth Army (13 divisions plus 2 in GHQ Reserve). Many British divisions were at little more than half strength, and none more than two-thirds, giving the Germans a 4:1 numerical superiority on Byng's front and over 8:1 on Gough's. At 8:30 am Gough ordered the 20th and 50th Divisions to be ready to move up to the front, and obtained retrospective permission from GHQ. Gough spent the morning at his own headquarters listening to reports as they came in – III Corps forward zone was already reported overrun by 10 am – and reading reports of the rounding up of labourers and pioneers into ad hoc fighting units, as he would have been putting himself out of communication had he attempted to tour the front. At around 1 pm General Humbert arrived, telling Gough that he had only a skeleton staff but no troops to send (je n'ai que mon fanion – "I've only the pennant on my car"), and promising to lobby GQG to send French divisions. At 2 pm, after studying aerial reconnaissance reports (the fog had cleared enough by 12:30 pm for British planes to be launched), Gough ordered the corps commanders to begin a fighting retreat, described by Beddington as "a right and brave decision arrived at very quickly". He was disinclined to speak to Lawrence or Davidson again, and disappointed not to hear directly from Haig himself that day. In the afternoon he visited his corps commanders one by one. Formal orders to fall