e point to be reached and the
object to be attained, the route to be pursued and the hour at which
they will be expected to be in position. They should be informed what
corps are marching either on the same roads with them or on side-roads
to the right or left in order that they may govern themselves
accordingly; they should receive whatever news there may be of the
enemy, and have a line of retreat indicated to them.[36]

All those details whose object it is to prescribe each day for the
chiefs of corps the method of forming their columns and placing them in
position are mere pedantry,--more hurtful than useful. To see that they
march habitually according to regulation or custom is necessary; but
they should be free to arrange their movements so as to arrive at the
appointed place and time, at the risk of being removed from their
command if they fail to do so without sufficient reason. In retreats,
however, which are made along a single road by an army separated into
divisions, the hours of departure and halts must be carefully regulated.

Each column should have its own advanced guard and flankers, that its
march may be conducted with the usual precautions: it is convenient
also, even when they form part of a second line, for the head of each
column to be preceded by a few pioneers and sappers, provided with tools
for removing obstacles or making repairs in case of accidents; a few of
these workmen should also accompany each train: in like manner, a light
trestle-bridge train will be found very useful.

4. The army on the march is often preceded by a general advanced guard,
or, as is more frequent in the modern system, the center and each wing
may have its special advanced guard. It is customary for the reserves
and the center to accompany the head-quarters; and the general advanced
guard, when there is one, will usually follow the same road: so that
half the army is thus assembled on the central route. Under these
circumstances, the greatest care is requisite to prevent obstructing the
road. It happens sometimes, however, when the important stroke is to be
made in the direction of one of the wings, that the reserves, the
general head-quarters, and even the general advanced guard, may be moved
in that direction: in this case, all the rules usually regulating the
march of the center must be applied to that wing.

Advanced guards should be accompanied by good staff officers, capable of
forming correct ideas as to the