Its ditches are unprotected.
The _lunette_ (Fig.

46) has nearly the same defects as the redan.
The _mitre_, or _priest-cap,_ (Fig.

47,) may be employed with advantage when a cross-fire is required on the capital of the work.

The _star-fort_ has all the defects, without the merit of simplicity, which belong to the polygonal redoubt.
The _bastion-fort_ (Fig.

48) more fully satisfies the conditions of a good defence than any other plan; but it is less simple and easy of execution.