So far the French piece did all expected of it. The German piece had proved its ability only to blow up permanent fortifications, and this was nullified immediately by the action of the French in abandoning the concrete shelters and moving their own guns into newly and quickly-constructed trench forts. A THING UNDREAMED OF. But the thing that neither side had dreamed of was the settling down of the war on the west front into an eternal line of opposing trenches to face each other for years. That it did so was due to the monumental blunders on the part of the German staff in allowing itself to be outmaneuvered and beaten back from the gates of Paris by numerically inferior forces, and still further outmaneuvered in the extension of the lines northward in that famous series of flanking movements which finally reached the sea. It was their success in driving the German army to earth when it was stronger than they were that saved the Allies, and gave them the breathing time required in which to further their preparations and train new troops, and likewise it is this same mode of trench warfare which has made their task so difficult when they have taken the offensive. Against ordinary trench lines, as known in the early stages of the war, the French field pieces were more effective than the heavy cannon of the Teutons, just as they had been in the open. Shooting in flat trajectory across the trench, and exploding just above it, the shrapnel scattered more death downward than the heavy projectile could scatter upward after it had buried itself in the soft earth. But with the continuous line of trenches stretching from Switzerland to the sea, with consequent impossibility of out-flanking, demonstrated by the Germans to their sorrow in repeated repulses of their drives to cut through to Calais, each side felt justified in replying to the artillery of the other by digging deeper and more permanently, with many feet of shelter overhead. This ended the effectiveness of shrapnel except for the repulse of attacks, and again the heavy guns swung into the position of pre-eminence. A SITUATION ALMOST BEYOND CONTROL. It was at this stage, however, that both sides realized how totally inadequate the supply of these heavy guns and ammunition was to cope with the situation. While the heavy gun was more effective in blasting out the enemy from his dugouts than the field piece, it required many times the artillery power which either side possessed to handle the job. Then commenced the race of the ammunition and gun factories to turn out their products by the ton where they had been turned out by the pound before; a race in which the Allies took and held the lead. With the greatly increased number of heavy guns it became possible to develop the famous curtain of barrage fire, also known as drum fire, with this type of ordnance, as well as with shrapnel.