But even they cannot remain permanently in touch with the enemy, because they, too, must send in their information by messenger, their strength thus rapidly diminishing, and they, in turn, will require relief.
If permanent observation of a yet distant enemy is necessary, we must turn to other means. It will, then, be as well to send out whole reconnoitring squadrons or troops (F.D.O.,[15] 128) towards the enemy, and through them maintain a permanent tactical observation.
These serve as a patrol reserve and collecting station for information, remaining day and night in touch with the enemy, and, of course, will also require periodical reliefs.
It goes without saying that, in addition to these squadrons, single patrols may be despatched in important directions from the main body of the Cavalry, whose duty it will be to report to the latter direct.
These, again, must send off their reports by several men, whilst those despatched from the patrols sent out by the reconnoitring squadrons will often, owing to the shorter distance and the nearness of the support, be able to avail themselves of the despatch riders. In general, it cannot be insisted upon too much that the despatch rider, so very popular in peace, can only be very occasionally employed in War in the interval before the enemy's Cavalry is completely beaten out of the field. In peace a man is always riding in his own country; if he himself has not a map, he has at least been instructed from a map, and every civilian will help him out. Even if he stumbles up against an enemy's patrol they will generally let him pass unnoticed; but it is quite different in War. Here even a patrol leader has rarely got a map. The despatch rider rides across thoroughly unknown districts, coming in contact with a foreign, perhaps hostile, population; he cannot make himself understood, if, indeed, he is not obliged to avoid them. The enemy's patrols are also everywhere, and if anything happens to his horse the message does not arrive. Further, the enormously increased distances to be traversed in modern War have to be taken into account, and these alone render the despatch of single horsemen a very doubtful undertaking. We must, therefore, recognise that the conveyance of reports by individual despatch riders is only possible under very limited conditions, and within the districts fully controlled by one's own troops, and that even in one's own country reconnoitring patrols sent out to a great distance can only be very occasionally employed.
Here we come upon an increased difficulty in the whole system of intelligence, and yet all reconnaissance is useless unless the return of information works without a hitch. We must, therefore, endeavour to regulate it accordingly.
Above all, the connection between the reconnoitring squadrons and the main body by relays must be very carefully assured, and their strength must be proportionate to the number of the enemy's patrols moving in the district. In these cases a co-operation between Cavalry and cyclists will be of service, whilst within the radius which we completely command the whole rearward intelligence service, so far as it can move upon roads, must be left as much as possible to cyclists.
Fundamentally, no Cavalry soldier should be allowed to ride to the rear without pressing circumstances. This is an absolute necessity if we are to spare our valuable and almost irreplaceable horses. Towards these safe lines of communication all reports must be directed, in order to be forwarded with the utmost rapidity by fresh horses or cyclists.
If these main roads do not run as far as the reconnoitring squadrons, in order to allow of the patrols making use of them without long detours, then further collecting stations, protected by other troops, must be interpolated. (F.D.O., 273.)
Occasionally the Cavalry Telegraph equipment may be of assistance, but we must not expect too much from it in periods of rapid movement, because since its application depends upon a number of favourable circumstances, its value in such changing conditions is more or less illusory.