Lastly, in winter quarters, the rigour of the season may also be a reason for breaking up the advanced guard into a line of posts, because it is easier to find shelter for it in that way.
The use of a reinforced line of outposts was brought to great perfection by the Anglo-Dutch army, during the campaign of 1794 and 1795, in the Netherlands, when the line of defence was formed by brigades composed of all arms, in single posts, and supported by a reserve. Scharnhorst, who was with that army, introduced this system into the Prussian army on the Passarge in 1807. Elsewhere in modern times, it has been little adopted, chiefly because the wars have been too rich in movement. But even when there has been occasion for its use it has been neglected, as for instance, by Murat, at Tarutino. A wider extension of his defensive line would have spared him the loss of thirty pieces of artillery in a combat of out-posts.
It cannot be disputed that in certain circumstances, great advantages may be derived from this system. We propose to return to the subject on another occasion.
CHAPTER VIII.
Mode of Action of Advanced Corps
We have just seen how the security of the army is expected, from the effect which an advanced guard and flank corps produce on an advancing enemy. Such corps are always to be considered as very weak whenever we imagine them in conflict with the main body of the enemy, and therefore a peculiar mode of using them is required, that they may fulfil the purpose for which they are intended, without incurring the risk of the serious loss which is to be feared from this disproportion in strength.
The object of a corps of this description, is to observe the enemy, and to delay his progress.
For the first of these purposes a smaller body would never be sufficient, partly because it would be more easily driven back, partly because its means of observation that is its eyes could not reach as far.
But the observation must be carried to a high point; the enemy must be made to develop his whole strength before such a corps, and thereby reveal to a certain extent, not only his force, but also his plans.
For this its mere presence would be sufficient, and it would only be necessary to wait and see the measures by which the enemy seeks to drive it back, and then commence its retreat at once.
But further, it must also delay the advance of the enemy, and that implies actual resistance.