21; II. iv. 4; V. iii. 52; VII. v. 18, and VI. ii. 13; "Anab." I.
ix. 27; II. i. 9; where "adjutants," "orderlies" would seem to be
implied.

[6] Al. "to prevent whole divisions losing their way." Cf. "Anab."
VIII. iii. 18.

Again, if there is prospect of danger on the march, a prudent general
can hardly show his wisdom better than by sending out advanced patrols
in front of the ordinary exploring parties to reconnoitre every inch
of ground minutely. So to be apprised of the enemy's position in
advance, and at as great a distance off as possible, cannot fail to be
useful, whether for purposes of attack or defence; just as it is
useful also to enforce a halt at the passage of a river or some other
defile, so that the men in rear may not knock their horses all to bits
in endeavouring to overtake their leader. These are precepts known, I
admit, to nearly all the world, but it is by no means every one who
will take pains to apply them carefully.[7]

[7] See "Econ." xx. 6. foll.

It is the business of the hipparch to take infinite precautions while
it is still peace, to make himself acquainted with the details, not
only of his own, but of the hostile territory;[8] or if, as may well
betide, he personally should lack the knowledge, he should invite the
aid of others[9]--those best versed in the topography of any district.
Since there is all the difference in the world between a leader
acquainted with his roads and one who is not; and when it comes to
actual designs upon the enemy, the difference between knowing and not
knowing the locality can hardly be exaggerated.