During 1915, the strength of the apparently frail barrier on the western front to which Forester referred had become evident. Using machine guns in combination with barbed wire and elaborate trench fortifications, the Germans repelled all attacks, often with stunning losses for the troops taking the offensive. The key weapon they employed was the machine gun. A trained team could bring it into use within four seconds. It equalled the firepower of fifty riflemen while presenting a virtually invisible target. "Six machine-guns could hold up a brigade; one gun could halt two battalions before they had got 200 yards from their front line."2 At the Battle of Loos, a preview of the greater bloodletting at the Somme, the slaughter produced on the morning of September 26, 1915, by the deadly combination of barbed wire and machine guns horrified even the enemy. "Numbers of German machine-gunners and riflemen stopped shooting," historian Trevor Wilson writes of the attack by the British 21st and 24th Divisions "because they had not the heart to continue the massacre."