sive that it may be of advantage to deal a blow
with the concentrated strength. Equally on the strategic offensive,
dispersion may be necessary, as when the enemy retreats eccentrically;
or if it is necessary to occupy districts of considerable size to
break down the resistance of the hostile population, or to interrupt
railway communication over a considerable area.

Finally, all principles fall to the ground where the enemy's Cavalry
is finally beaten out of the field, or by a succession of mistakes he
gives openings which we can seize with advantage. Thus our conduct
always remains dependent on the topographical nature of the country,
on our own purpose and the opposition of the enemy, and only one law
governs all cases--namely, expediency. The greater art of leading will
naturally be required when the necessity arises to operate with more
or less widely-separated columns. In all such cases everything depends
on the endurance of one's troops. The principal difficulty in the way
of execution lies in harmonizing and maintaining the movements of the
separate detachments.

If one has to deal with Infantry only, then, since their rate of march
is almost always the same, it is easy to calculate approximately where
the several columns may be found; but it is quite different when one
comes to deal with Cavalry, where the different Leaders may adopt very
different rates of movement, or may have such variations forced upon
them by other circumstances, and hence one has always to deal with
quite indeterminable factors. This difficulty can never be altogether
eliminated; one can only counteract it by laying down from the very
first instructions for the advance of the several columns, according
to time and space, from which no deviation is to be permitted without
sufficient reasons, and organizing the circulation of orders and
intelligence in such a manner that it will work with certainty. These
two precautions supplement one another. If one can calculate
approximately where the several detachments are to be found at a given
time, then reports can be sent by the shortest way, and will reach
their destination without delay.

It will be decidedly advisable that all detachments should report to
Headquarters, and if possible to all adjacent columns, without
distinct instructions, and at certain time intervals, both as to their
advance, their bearing in relation to adjacent columns, as also any
news they may have obtained about the