Technical improvements, such as the longer range and quicker fire of the guns, swifter means of communication and of signaling and the like, not to speak of other considerations due to experience, have so changed the old tactics that a line of battle is now more than ten times as long as it was only a few years ago. At Sadowa, with 215,000 men, the Austrians had a front of only 10 kilometers; at Mukden the attacking line of the Japanese, who had only 170,000 men, extended for 110 kilometers. “The broken line,” writes Bernhardi, “is to-day the only battle formation of the infantry.” To-day, officers and men fight in trenches and take every advantage of the inequalities of the ground; in 1870 it was considered disgraceful to take such advantages and the officers stood erect in the most deadly fire. In consequence of the length of the lines a check in one quarter is no longer so serious a matter as it used to be; a modern battle is a succession of single engagements of which the victor only needs to win a good majority. The commander no longer takes up a position, as Napoleon did at Leipzig, where he can oversee the whole field of operations; the best place for him is some railroad junction or central telephone station, with wireless and ordinary telegraph equipment, where messages can constantly be sent and received, and to and from which he can despatch troops, automobiles, motor-wagons or aeroplanes. One of the chief modern problems is supplying sufficient ammunition for quick-firing guns—the baggage trains must not be so long as to hinder the advance of the troops, yet where there are many guns and each shoots off hundreds of shots a minute, great quantities of ammunition are needed. [Illustration: Transmitting and Receiving Orders by Telephone] [Illustration: Telegrams] [Illustration: Giving Orders] I have spoken of military service being almost universally compulsory in Europe. This means that every man of a certain age and with the requisite health and strength is obliged to report for duty. It has not hitherto meant that every eligible recruit was obliged to serve. In Germany a large contingent, even of the capable, was formerly excused. In 1910, for instance, nearly 235,000 were declared more or less unfit for service, although in France they would probably nearly all have been accepted. By the German army bills of 1911, 1912 and 1913 indeed the numbers of those required for active service were steadily increased: 9,482 in the first named year, some 29,000 in the second, and then the great increase of 63,000 in the third. But there were still, up to the present mobilization, some thirty thousand able-bodied recruits who could not be placed.