On August 9, 1915, a squadron of thirty-two large French aeroplanes carrying explosives, and accompanied by a number of lighter machines to act as scouts, set out to bombard the important mining and manufacturing town of Saarbruecken, on the river Saar, in Rhenish Prussia. This was where the first engagement in the Franco-Prussian War of 1870 was fought. Owing to mist and heavy clouds, only twenty-eight of the aeroplanes succeeded in locating the town, where they dropped one hundred and sixty bombs of large caliber. A number of German aviators ascended as soon as the flotilla's arrival had been signaled, and a lively skirmish ensued between them and the French scouts. The results and casualties of the raid have not leaked out. The German General Staff was evidently not unacquainted with the fact that the Allies had a big "drive" in contemplation. Most of the fighting had been forced by the Germans with ever-increasing violence and energy. Toward the middle of August, 1915, their attacks became fiercer still. After a deadly bombardment that literally flattened the countryside, and in which shells of all calibers as well as asphyxiating gas bombs were hurled against the French positions between the Binarville-Vienne-le-Chateau road and the Houyette ravine in the Argonne, the German infantry dashed from their trenches in great numbers and close formation and charged across the intervening ground. So furious was the onslaught that the French were driven well back out of their shattered defenses. Within a few hours strong reenforcements hurried to the spot enabled the French to deliver a counterattack and recover some of the lost ground. Simultaneously, the Germans attempted to storm the French position in the neighborhood of La Fontaine-aux-Charmes, but with less success. During the last week of July and the first half of August, 1915, large bodies of German troops were detached from the armies operating on the eastern front and poured into France and Flanders. Different estimates fix the numbers at from 140,000 to 200,000.