=241. A War of Science.= Every movement in the war had to be planned as exactly as possible. This was a war of science, rather than a war of dashing adventure, as those in the past had been. Before attacks were made on the enemy, a barrage, or curtain-like rain of shells, was turned on his lines. This "curtain of fire" moved forward at a fixed rate, and the men walked behind it. They had strict orders to go only so many yards a minute, or their own guns would kill them. [Sidenote: =Use of poison gas=] Poison gas was one of the new weapons of this war. It caused almost one-third of our losses in 1918. Science produced new gases so rapidly that inventors had to be continually making new gas masks to strain out the deadly fumes. Over thirty kinds of gas were used during the war. No one commander could be present at once on every part of the hundreds of miles of battle-lines, or even a small part of them. The war had to be carried on largely by telephone. The Americans strung one hundred thousand miles of wire in France. [Sidenote: =Pershing trained for his work=] =242. Pershing Heads the Army.= The youngest of American generals, John Joseph Pershing, was put at the head of the American forces. The choice of Pershing was hailed everywhere as a wise one. A war so immense and mechanical needed a general who had studied the art of war thoroughly, as Pershing had. He had seen much actual fighting, and was the only American general who had commanded a division in actual war. He carried with him the love and respect of all national guardsmen. They would have followed him anywhere he wished to lead. [Illustration: THE TANK, A NEW WEAPON IN THE WAR] We have already heard how he had routed Villa's bandits in Mexico. He had also led a charge of colored troops against the Spaniards in Cuba, and had conquered a powerful savage tribe in the Philippines. Before he was sent to Mexico he had been governor of a province in the Philippines for four years. [Sidenote: =Fights squarely=] =243. A Boy Who Was Made of Fighting Stuff.= As a boy, Pershing was brave and modest, with the ability to stay by a hard task until he finished it. John was a hardy, active boy. He played at mimic war and attended school. He played "hookey," and got into fights with his fellows, but he was square. One day the father saw the signs of battle-torn clothes and a bruised face. "Been fighting? Never let any boy say that he has licked you," was the father's remark. John had expected a whipping. [Illustration: _From a Photograph by Clinedinst_ JOHN J. PERSHING] At day school he was a plodder. But he did win a prize, a nicely bound volume of the _Life of Washington_. This was offered by the president of the school board. John's mother was there. The children clapped and called for a speech. "I'm sorry you didn't all win a prize. I'm going to grow up like Washington," he said. [Sidenote: =Studies at West Point=]