Offensive Fortification, shews how to besiege and take a fortified place; it further teaches a general how to take all advantages for his troops; the manner of encamping, and method of carrying on either a regular or irregular siege, according as circumstances may direct.
Defensive Fortification, shews a governor how to make the most of a garrison committed to his care, and to provide all things necessary for its defence.
Regular Fortification, is that built in a regular polygon, the sides and angles of which are all equal, being commonly a musquet shot from each other, and fortified according to the rules of art.
Irregular Fortification, on the contrary, is that where the sides and angles are not uniform, equi-distant, or equal; which is owing to the irregularity of the ground, vallies, rivers, hills, and the like.
To Fortify inwards, is to represent the bastion within the polygon proposed to be fortified; and then that polygon is called the exterior polygon, and each of its sides the exterior side, terminating at the points of the two nearest bastions.
To Fortify outwards, is to represent the bastion without the polygon proposed to be fortified, and then the polygon is called the interior polygon, and each of its sides the interior side, terminating in the centres of the two nearest bastions.
Elementary Fortification, by some likewise called the theory of fortification, consists in tracing the plans and profiles of a fortification on paper, with scales and compasses; and examining the systems proposed by different authors, in order to discover their advantages and disadvantages. The elementary part is likewise divided into [regular] and [irregular fortification], which see.
Front Fortification, any proportion of the body of a place, consisting of two half bastions and a curtain.
Practical Fortification, consists in forming a project of a fortification, according to the nature of the ground, and other necessary circumstances, to trace it on the ground, and to execute the project, together with all the military buildings, such as magazines, store houses, barracks, bridges, &c.
The names of every part of a Fortification; and first of lines, which are divided into right lines, and curve lines.