1. So far as is possible, guns should be kept _hidden from the enemy_
till the moment of opening on him. They may be masked by the ground, or
other cover, natural or artificial, or by troops placed in front of
them. The surprise will add much to their effect. Moreover, concealed,
they will be less exposed to be taken. Nothing discourages troops more
than the loss of a battery at the beginning of an action.
2. A desultory and indiscriminate artillery fire will accomplish
nothing. To effect any thing important, it must be _concentrated on some
object_; and the fire must be persevered in till the desired effect has
been produced.
3. It is a general principle that artillery should not reply to the
enemy's batteries, unless compelled to by their effect on our own
troops. To obtain the most decisive effects from artillery fire, it
should be directed _on the enemy's troops_, instead of his guns.
4. If it should become advisable to silence one of his batteries, it
will be done more promptly and effectually by the employment, for this
purpose, of _two_ of our own batteries, than of a single one.
5. There is usually great advantage in keeping our batteries constantly
_shifting their position_; for then--
(1.) They have the effect of a surprise, by opening on the enemy at
some unexpected point.
(2.) They make the enemy believe our guns to be more numerous than they
really are.
(3.) They are in less danger of being captured.
But these changes of position are attended with this inconvenience, that
they expose the horses to be taken in flank by the enemy's batteries and
sharpshooters.
6. The movements of a battery in the field should be _as rapid as
possible_; for, while moving, it is helpless and exposed.
Moreover, celerity of movement and accuracy of fire will often more than
compensate for inferiority in the number of guns; as was the case at the
battle of Palo Alto, in the Mexican War, where the enemy's guns
outnumbered ours two to one.