1. When used to _prepare for an attack_ of infantry or cavalry,
artillery concentrates as much fire as possible on the point where the
attack is to be made, in order to overcome the resistance there, and
thus make success easy.
2. When there are several points on which our fire should be directed,
we must not batter them all at once, but concentrate our whole fire on
them _in succession_.
3. In attack, artillery should _not be split up_ among different
brigades or divisions; else no decisive result can be expected from it.
Whole batteries, used together, will have a more telling effect than if
scattered over the field in separate sections.
In no case should less than two pieces be used together; for, while one
piece is being loaded, the piece and its gunners need the protection of
another one ready to be discharged.
4. Pieces in support of an infantry column of attack should never be in
its rear, but _on its flanks_, near its head, in which position it will
best encourage the infantry. But if a battery have already a position
from which it can afford to the attack effective assistance, it should
remain in it; sending a few pieces to accompany the infantry, which
always greatly values artillery support.
5. Powerful effects may be produced by the _sudden assemblage of a great
number of guns_ on some particular point. This was a favorite
manoeuvre of Napoleon; who, by his rapid concentration of immense
batteries of light artillery on the important point, usually obtained
the most decisive results. At Wagram, for instance, when Macdonald's
column was ready to make its great charge on the Austrian centre,
Napoleon suddenly massed one hundred guns in front of his own centre,
and made it advance in double column at a trot, then deploy into line on
the leading section, and concentrate its fire on the villages forming
the keys to the enemy's position, in front of his right and left wings
respectively; each battery opening its fire on arriving at half-range
distance. The effect was overwhelming.
6. The _nearer_ artillery delivers its fire, the more powerful, of
course, are its effects. Horse artillery, in sufficient strength,
attacking the enemy at short grape-shot distance, say within three
hundred or four hundred yards, may lose half its pieces, but with the
other half it will probably decide the battle at that point.
At Palo Alto, Duncan's rapid closing with his guns to less than half
range, drove back the Mexican right wing, which could not stand the
destructive fire.
7. _Horse artillery_ does not usually attempt to follow up cavalry in
its attack; but takes a position to cover its retreat, if repulsed, or
to push forward in support, in case of success.
8. When cavalry has to _debouch from a defile_, horse artillery may
render it most effectual assistance, by taking a position that will
enable the cavalry to form without fear of being charged and destroyed
while forming.