If we reflect on these four points in the whole of their effects, we see that an important fortress in a direct and in an indirect way certainly gives some security to a much greater extent of cantonments than we should think at first sight. “Some security” we say, for all these indirect agencies do not render the advance of the enemy impossible; they only make it more difficult, and a more serious consideration; consequently less probable and less of a danger for the defensive. But that is also all that was required, and all that should be understood in this case under the term covering. The real direct security must be attained by means of outposts and the arrangement of the cantonments themselves.
There is, therefore, some truth in ascribing to a great fortress the capability of covering a wide extent of cantonments lying in rear of it; but it is also not to be denied that often in plans of real campaigns, but still oftener in historical works, we meet with vague and empty expressions, or illusory views in connection with this subject. For if that covering is only realised by the co-operation of several circumstances, if it then also only produces a diminution of the danger, we can easily see that, in particular cases, through special circumstances, above all, through the boldness of the enemy, this whole covering may prove an illusion, and therefore in actual war we must not content ourselves with assuming hastily at once the efficacy of such and such a fortress, but carefully examine and study each single case on its own merits.
- As covering a province not occupied. If during war province is either not occupied at all, or only occupied by an insufficient force, and likewise exposed more or less to incursions from flying columns, then a fortress, if not too unimportant in size, may be looked upon as a covering, or, if we prefer, as a security for this province. As a security it may at all events be regarded, for an enemy cannot become master of the province until he has taken it, and that gives us time to hasten to its defence. But the actual covering can certainly only be supposed very indirect, or as *not