Increased artillery firing at many points in Flanders and northern France first gave the Allies the impression that the Germans were planning a new offensive on a large scale against their left wing, in an attempt to blast a passage through to Calais and Dunkirk. By February 7, 1916, the Allies were thoroughly awake to the possibility of a big blow impending somewhere in the west. The sweep through Serbia had released several hundred thousand men for service elsewhere. For a month the Germans had been hammering and probing at Loos, Givenchy, Armentieres, and other points with the evident object of finding a weak spot. Along the Neuville-Givenchy road especially the Germans made no fewer than twenty-five determined attacks between the 1st and 17th of February, 1916. Their later attacks developed more to the north, near Lievin, where heavy trench fighting occurred, with no important results either way. At the beginning of February, 1916, the 525-mile battle front in the west was held on one side by about 1,250,000 Germans--an average of 2,500 to the mile--as against quite 2,000,000 French, about 1,000,000 British, and 50,000 Belgians. But this superiority in numbers on the allied side was neutralized by the strength of the German defense works plus artillery. None of the Allies' undertakings had, so far, been carried out to its logical--or intended--conclusion. Whether this was due to weakness, infirmity of purpose or lack of coordination, remains to be told some future day. By the middle of the month it became apparent, from their expenditure of men and munitions, that the German General Staff were determined to make up for their past losses and to recapture at least some of the ground taken from them by the Allies. It seems hardly credible that all these fierce attacks were mere feints to withdraw attention from their objective--Verdun. They had no reason to fear a French offensive in the immediate future. For one thing the condition of the ground was still too unfavorable. The French at this stage occupied practically the entire semicircle from Hill 70 to the town of Thelus, excepting a portion between Givenchy and Petit Vimy. Hill 140, the predominant feature in the district, was almost all in French hands. The line between La Folie and the junction of the Neuville-St. Vaast road covered the Labyrinth, which the French had won in the summer of 1915, and it was here that the main force of the German attacks was launched. The French positions on the heights commanded every other position that the Germans could possibly take within the semicircle, and naturally gave the former an immense advantage for their next offensive.