Cæsar realized fully the value in war of mechanical appliances, and took careful measures before he left Italy to supply his army adequately with them, and also with men trained to use them. Besides the fighting men strictly considered, Cæsar took a considerable number of engineers with him, and expert men for building bridges, and doing mechanical work of many kinds. The ingenious and frequent use that Cæsar made of these men and of mechanical appliances was the most powerful single factor that contributed to his success. The Swiss departing from Switzerland by another route, Cæsar pursued them, and defeated a fourth of them in a battle on the banks of a river which the other three-fourths had crossed. He then built a bridge over the river and sent his army across. This feat alarmed the Swiss more than their defeat; because Cæsar had built the bridge and sent his army across in one day, whereas they had consumed twenty days in merely crossing. The Swiss pleaded to be allowed to proceed; but Cæsar was obdurate. A battle followed, in which the Swiss, though greatly superior in numbers and reinforced by 15,000 allies, were decisively beaten; not because of inferior courage or warlike skill, but by reason of inferior equipments, mechanical appliances and weapons. Cæsar's next battle was with the Germans. It was won, if not precisely with inventiveness, at least with "brains." He learned that the German matrons had declared, after certain occult proceedings, that Heaven forbade them to fight before the new moon. Apprehending his opportunity, he advanced his forces right up to the German camp, thereby forcing them as valiant soldiers to come out and fight. Fight they did, but under an obvious psychological disadvantage, and with the natural result. In this battle, as in others between the Romans and the barbarians, it was noticeable that although their first onslaught was fine, the barbarians seemed to be at a loss afterwards,--if anything unexpected occurred, or if any reverse was sustained; whereas the Romans--and especially Cæsar himself--never behaved so well as when threatened with disaster. This may be expressed by saying that the barbarians, as compared with the Romans, were wholly inferior in the inventiveness needed to devise a new plan quickly. Not long afterward, Cæsar advanced against the town of Noviodunum. He soon saw that he could not take it by storm; and so he brought forward his mechanical siege appliances. The psychological effect of these on the barbarians was so tremendous that they at once pleaded for terms of surrender.