The essential consideration therefore is a good choice of positions; shelter from the approach of an invasion on the flanks, and the avoidance of enormous expenditure in the attempt to defend all points. Let us suppose that Metz had been rendered impregnable, or at least so provided with defences that it could have held out for six months; and certainly the thing was possible. In the first place we should not have lost that town, and secondly the war, notwithstanding our deficiencies in soldiers and in artillery, might have taken quite another turn. Greater sacrifices on the part of the enemy, more prudence, and a still greater loss of men, would have been required to constrain us to a peace accepted before the cannon's mouth. War is made now a-days with armies a million strong; this is all very well while the invading force meets no very serious obstacle, either in front of it or on its flanks; when the combinations which such a vast display of forces necessitates are not disturbed at any point, and when the strategic operations upon the ground succeed each other with perfect precision, as one might trace them on a map in our studies. But these enormous agglomerations of men could give rise in a single day to appalling perils, after a grave check on one of their flanks. Such masses can be advanced, fed, and manoeuvred only by means of a very complicated, and therefore delicate and easily deranged machinery. The Germans asserted that by the possession of Alsace and a part of Lorraine we had a hold upon Germany. Now their country is almost dove-tailed into France. The future will show whether that will greatly benefit them. In 1870 and 1871 we saw what could be accomplished by the little fortress of Belfort; which was perhaps the only one among our strong places possessing guns of long range, and a garrison well commanded and determined to defend itself. It persisted in maintaining the offensive over a circle of from twelve to sixteen miles, thanks to a few rifled cannon with which the ramparts were furnished, and which protected sorties through a radius of three to four miles. For a month it hindered the planting of siege batteries; and, in spite of a bombardment of seventy-three days, the town had only four of its houses burned. This defence is instructive, and shows that the old defensive system has had its day. During the siege the batteries of the besieged hardly suffered at all, and had recourse to indirect firing--that is, they fired over the barracks from the gorge of the castle without seeing the mark, but regulating by observation. This indirect firing, which took no account of the plan of the crests of the defence, and which thus enabled a powerful fire to be directed to any point, without regarding the faces, produced a great effect on the batteries of the enemy, who, on his side, could not see these guns, and did not know how to regulate his fire.