The expenditure entailed by such a system of defence is unquestionably enormous. But as respects this question there is to all appearance an unwillingness to realize exactly the new state of things produced by artillery of long range. The expenditure involved in the successive systems of defence from ancient times downwards has been a continually increasing one. The wall built round Paris by Philippe-Augustus, would not cost, the running yard, as much as that of Charles V.; the latter, again, must have been less expensive than the bastioned fronts of Louis XIII., and these again would be far from necessitating the outlay (_i.e._ estimated by the running yard, and reckoning detached forts) occasioned by the fortification of Paris under Louis Philippe. Similarly the mounting of four or five trebuchets, and the movable towers required for attacking a fortified place before fire artillery was employed, cost less than the manufacture of the artillery used at the siege of Turin in 1535. The latter again would be far less costly than the French and English artillery at the siege of Sebastopol. Whereas at the time when smooth-bore guns were used a place might be attacked with about sixty pieces, five times the quantity are needed now; since it is necessary to operate over a much more extensive area. War is therefore a game which tends to become more and more costly, and especially siege warfare. Are we then to conclude that nations will become disgusted with warfare on account of the frightful expense it involves? This is not probable. At the present day, as in times past, that which costs most is defeat. With forty millions well laid out in France, before the war of 1870, and from forty to eighty millions spent in the war itself, we probably should not have had to pay the four hundred millions which this war cost us, and we should not have lost two provinces which are certainly worth still more than that sum. Parsimony in military preparations, in times of serious change, such as ours, is ruinous. The principles to be followed may be summed up as follows: Commit yourself to no superfluous outlay, but spend all that is necessary. Besides, is it after all certain that a good system of territorial defence is so costly as some allege? Is it a question of building something like a Chinese Wall on our eastern frontier? Is it likely that if a few strong positions rendered impregnable without unnecessary works enabled us to keep an army of observation two hundred thousand strong, secure from any surprise in the elevated valleys bounded by the ranges of hills which stretch from the Jura along Belfort, Remiremont, Epinal, Langres and Dijon, and border the right bank of the Saône as far as Lyons, the Germans would be in a hurry to make their way a second time to Paris? If they experienced the slightest check on such a route, if they were obliged even to halt, what would become of them?