Of the retreat of the French army from Moscow to the Niemen, we shall say nothing, but this we may mention, that the Russian army following them left Kaluga 120,000 strong, and reached Wilna with 30,000. Every one knows how few men were lost in actual combats during that period. One more example from Blücher’s campaign of 1813 in Silesia and Saxony, a campaign very remarkable not for any long march but for the amount of marching to and fro. York’s corps of Blücher’s army began this campaign 16th August about 40,000 strong, and was reduced to 12,000 at the battle of Leipsic, 19th October. The principal combats which this corps fought at Goldberg, Lowenberg, on the Katsbach, at Wartenburg, and Mockern (Leipsic) cost it, on the authority of the best writers, 12,000 men. According to that their losses from other causes in eight weeks amounted to 16,000, or two-fifths of the whole. We must, therefore, make up our minds to great wear and tear of our own forces, if we are to carry on a war rich in movements, we must arrange the rest of our plan accordingly, and above all things the reinforcements which are to follow. CHAPTER XIII. Cantonments In the modern system of war cantonments have become again indispensable, because neither tents nor a complete military train make an army independent of them. Huts and open-air camps (bivouacs as they are called), however far such arrangements may be carried, can still never become the usual way of locating troops without sickness gaining the upper hand, and prematurely exhausting their strength, sooner or later, according to the state of the weather or climate. The campaign in Russia in 1812 is one of the few in which, in a very severe climate, the troops, during the six months that it lasted hardly ever lay in cantonments. But what was the consequence of this extreme effort, which should be called an extravagance, if that term was not much more applicable to the political conception of the enterprise! Two things interfere with the occupation of cantonments the proximity of the enemy, and the rapidity of movement. For these reasons they are quitted as soon as the decision approaches, and cannot be again taken up until the decision is over.