On our side, we might try to learn if the enemy knew of our coming, and how much he knew. A thin fringe of French had remained in the front-line trenches, with our men in place behind them. Thus our voices of different timbre, speaking the English tongue in regions where only French had been spoken, might not be heard if we forgot the rules of silence, which were as mandatory by custom as in a church or a library; and besides, if the Germans made a raid for information they would not take American prisoners. They did make some minor raids, capturing Frenchmen who, perhaps unwittingly when wounded or in the reaction from danger, and subject to an intelligence system skilled in humoring and indirect catechism, told more than they thought they were telling. Information that we had from German prisoners left no doubt that the Germans knew at least that the Americans were moving into the sector, but did not expect a powerful offensive. This, as we had anticipated, was discounted as being out of the question on the heels of the Saint-Mihiel offensive. Our new army, the Germans thought, had not the skill or the material for such a concentration, even if we had the troops. In our demonstration that we did have the skill and the energy, and that in one way and another we were able to secure the material even though it were inadequate, we were peculiarly American; and we were most significantly American in the adaptable exercise of the reserve nervous force of our restless, dynamic natures, which makes us wonderful in a race against time. We strengthen our optimism with the pessimism which spurs our ambition to accomplishment by its self-criticism that is never satisfied. On all hands I heard complaints by officers concerning lack of equipment, of personnel, of training, and of time. But no one could spare the breath for more than objurgations, uttered in exclamatory emphasis, which eased the mind. I could make a chapter out of these railings. Yet if I implied that the unit, whether salvage or aviation, hospital or front-line battalion, tanks or signal corps, or any other, would not be able to carry out its part, I was assailed with a burst of outraged and flaming optimism. And optimism is the very basis of the psychologic formula of war. Americans have it by nature. We lean forward on our oars. Optimism comes to us from the conquest of a continent. It presides at the birth of every infant, who may one day be president of the United States. Confidence was rock-ribbed in a commander-in-chief's square jaw; it rang out in voices over the telephone; it was in the very pulse-beats of the waiting infantry; it shone in every face, however weary. We had won at Château-Thierry; we had won at Saint-Mihiel; we should win again. The infantry might not conceive the nature of the defenses or of the fire they might have to encounter. So much the better. They would have the more vim in "driving through," said the staff.