At the time Mangin's Army was preparing to crush the enemy's front between the Aisne and St. Gobain, Horne's Army, on the Scarpe, attacked the salient east of Arras. On =August 25=, the Canadians, astride the Scarpe, and the left of Byng's Army captured the difficult positions of Monchy-le-Preux, Guémappe and Rœux, bringing their line into contact with the redoubtable position of Quéant-Drocourt, a ramification of the Hindenburg Line. On =September 2=, the Canadians attacked, progressing rapidly along the Arras-Cambrai road. Penetrating the German lines to a depth of 6 miles, they reached Buissy. [Illustration] On the night of August 30, the Australians, in the centre, furiously attacked and captured the formidable bastion of Mont-St-Quentin. On =September 1=, they entered Péronne, after desperate fighting. To flank this attack on the north, Bouchavesnes and Frégicourt were captured. Further south, on the Oise, Humbert's Army, in spite of the enemy's resistance, took Noyon and the high ground dominating the town. Advancing from the Ailette, towards Chauny, Mangin's left reached the outskirts of St. Gobain Forest, in the old lines of March 1918. Outflanked on the north, towards Cambrai, and on the south along the Oise, in the direction of La Fère, and violently attacked at the same time in the centre at Péronne, the Germans retreated towards the Hindenburg positions. The British and French forces drove back the enemy rear-guards, which were unable to hold the line of the Tortille and the Canal du Nord. On =Sept. 8=, the Allied front ran west of Arleux and Marquion, through Havrincourt, Épéhy and Vermand, then followed the Crozat Canal. IV.--THE OFFENSIVES AGAINST THE OUTWORKS OF THE HINDENBURG LINE. September 10-25. The Germans had reached the advanced defences of their famous Hindenburg Line, consisting of the old British lines lost in March. These formidable positions protected the ramparts of the Hindenburg Line, said to be impregnable. On =September 10=, the British 3rd and 4th Armies (Byng and Rawlinson) attacked between Havrincourt and Holnon. [Illustration] The 4th Army took Vermand, the western outskirts of Holnon Woods, and gained a footing in Épéhy and Jeancourt. On the 13th, after desperate fighting, it captured the woods and village of Holnon. The 3rd Army crossed the Canal du Nord, south of the Bapaume-Cambrai road, turned the positions from Havrincourt to Gouzeaucourt, and captured the greater part of them, the enemy resisting desperately. The same day (Sept. 12), the American 1st Army captured the whole of the St. Mihiel Salient, with 15,000 prisoners and 200 guns. (_See the Guide_: =The Battle of St. Mihiel=.) On the =18th=, a general attack was launched by the British 3rd and 4th Armies, in liaison with the French 1st Army. All the enemy's positions between Gouzeaucourt and Holnon were captured, with 10,000 prisoners and 150 guns.