iring over their heads_.

This was done by the French at Waterloo, apparently with great effect.
But the advantage is a doubtful one; for firing over our own troops,
especially with cast-shot or shell, is very dangerous to them, and is
apt to intimidate them. It moreover furnishes to the enemy a double
target. The shot which miss our troops will be apt to fall among the
guns behind them; and some of those which do not reach the guns, will
probably take effect among the troops in front of them.

3. But _very high_ points are unfavorable positions for batteries.
Batteries so placed would not command the ground immediately below them;
as guns cannot be depressed to fire below a certain angle without soon
destroying their carriages. And this would facilitate their capture;
for, once arrived on the ground near them, the assailants could not be
injured by their fire. It has been estimated that the slope in front of
a battery should not exceed one perpendicular to fifteen base.

4. When guns have to be used as a support to other parts of the line,
which is often the case, their capture might lead to serious
consequences. They should therefore have the ground clear of all
obstacles which may _mask their fire_, not only in front, but to their
right and left.

5. Although the most favorable position for guns is an eminence sloping
gradually towards the enemy, an _open and level plain_ is by no means an
unfavorable one; for, on such ground, the enemy will be visible at a
great distance, and our shot may act by ricochet, which causes more
destruction than ordinary point-blank firing.

For ricochet, firm and even ground is requisite; on soft or rough ground
it is not attainable.

6. In enfilading the enemy's position, or in raking his advancing
columns from head to rear, a _grazing fire_ is the most destructive that
can be used. This consists of a long succession of ricochets at low
heights. Where the ground is level and firm, we can obtain this fire at
a short distance from the enemy; as, on such ground, ricochet shots do
not rise much. But where the ground is uneven, to obtain such a fire, a
more distant position will be requisite.

7. _Muddy_ ground is unfavorable for artillery. Over such ground, its
carriages move slowly, and its fire is less effective. Balls cannot
ricochet; and shells often sink into the mud, and thus are either
extinguished or explode with but little effect.

Napoleon depended so much on his artiller