the Tenth Army front. By 20 May the French artillery was dominated by the German artillery reinforcements, which severely inhibited the consolidation of captured ground and preparations for more attacks. Despite the change from attempts at continuous battle to methodical attacks, with pauses to reorganise and consolidate, the French took less ground, fewer prisoners and suffered more casualties. Foch concluded that a breakthrough was unlikely until the German armies in France had been depleted to a far greater extent; he advocated small step-by-step attacks, using methodical and economical methods. Fayolle wrote that the advocates of continuous battle were subject to a "grand illusion" and criticised Foch and d'Urbal for making unrealistic demands. André Laffargue, an artillery officer, was prompted to write , an example of the trend to artillery-based tactics and infiltration by infantry. From 10 to 16 June the French fired with less effect than the fired from 3 to 9 May. The Germans had managed to fire a heavy artillery barrage of which stopped the French infantry attack and prevented troops moving up in support. Attempts to repeat the surprise of 9 May by ruses failed and a German counter-barrage had begun in no man's land within two minutes of the French infantry advance. The experience of the attacks on 16 June demonstrated that the effect of counter-battery fire, neutralising fire and changes in the pattern and timing of artillery-fire made no difference if the German wire was uncut when the infantry advance began. German field defences were dug in increasing quantity and complexity during the offensive and German artillery became much more active, as more guns and much more ammunition arrived at the battlefront. The new German defences around the area were on ground overlooked from the Lorette Spur, were more costly to defend and made Vimy Ridge more vulnerable to attack. The apparent lost opportunity on 9 May, when Vimy Ridge was captured in the first rush, led the French army commanders to conclude that more of the same could achieve a breakthrough if better organised, which formed the basis of the planning for the autumn offensives in Artois and Champagne. Pétain wrote that the attack on 9 May showed that a breakthrough was possible and that it could be achieved by careful preparation of communication trenches, jumping-off trenches and assembly positions, if the German defences were carefully reconnoitred and sufficiently bombarded by artillery. Since the