1. As guns in the field should generally play on troops instead of
batteries, there should be a _reserve of horse artillery_ to take the
enemy's batteries in flank, in case of need, as well as for other
purposes.
2. Though the ordinary use of artillery is against infantry and cavalry
only, special circumstances may render it expedient that a certain
portion of it should _respond to the enemy's batteries_. In this case,
not over one-third should be used for that purpose.
3. When we have _guns in abundance_, it might be sometimes advisable, by
using several batteries at once, to silence the enemy's guns, before
beginning to play on his troops.