Of all the projectile machines must be in play and favorably placed.

The position must neither be commanded, out-fronted, nor surrounded; but on the contrary ought, as far as possible, to command and out-front the enemy's position.

But even in the same position there are numerous modes of arranging an encampment, or of forming a line of battle, and to select the best of these modes requires great experience, _coup d'oeil_, and genius.

In relation to this point Napoleon makes the following remarks:-- "Ought an army to be confined to one single encampment, or ought it to form as many as it has corps or divisions?
At what distance ought the vanguard and the flankers to be encamped?
What frontage and what depth ought to be given to the camp?
Where should the cavalry, the artillery, and the carriages be distributed?
Should the army be ranged in battle array, in several lines?
And if it should, what space should there be between those lines?
Should the cavalry be in reserve behind the infantry, or should it be placed upon the wings?
As every piece has sufficient ammunition for keeping up its fire twenty-four hours, should all the artillery be brought into action at the beginning of the engagement, or should half of it be kept in reserve ?" "The solution of these questions depends on the following circumstances:--1st.

On the number of troops, and the numbers of infantry, artillery, and cavalry, of which the army is composed.2d.