A work is not therefore always to be condemned, because it is in the neighbourhood of a height; for if it be properly defiladed from that height, it will receive a great advantage over the approaches of the besiegers, carried on down an inclined plane towards it. But a work to be properly constructed in the neighbourhood of heights, must not uniformly preserve the same distance from those heights, unless their summits be all upon the same level; but must approach them at their lowest parts, and recede from them as they rise; thus will the necessary plane of defilement preserve nearly the same degree of obliquity throughout. _The Dimensions in the following Table of Vauban, are thus applied_: The _Fort_ is mostly for squares. The _Little_ for citadels, commonly pentagons. The _Mean_ for all fortifications from the hexagon and upwards. The _Great_ is seldom used but in irregular fortifications, and particularly on rivers. [7] The compiler must here apologize for coining the word _defiladed_, which he is obliged to do, never having seen this subject treated of in English. But the French use the word _defile_ in a contrary sense to _enfile_; and as we admit the words enfilade and enfiladed from the latter, we cannot refuse the terms defilade and defiladed from the former. _Principal Dimensions of Fortifications, according to_ VAUBAN. +-----------------+-------+-------------+--------+----------+ | |Side of| Length of |Faces of|Capital of| | |Polygon|Perpendicular|Bastions|Ravelins | +-----------------+-------+-------------+--------+----------+ | Forts. | 80 | 10 | 22 | 25 | | | 90 | 12 | 25 | 28 | | | 100 | 12½ | 28 | 30 | | | 110 | 14 | 30 | 35 | | | 120 | 15 | 33 | 38 | | | 130 | 16 | 35 | 40 | | | | | | | | Little | 140 | 20 | 40 | 45 | | Fortification. | 150 | 21 | 42 | 50 | | | 160 | 23 | 45 | 50 | | | 170 | 25 | 47 | 52 | | | | | | | | Mean. | 180 | 30 | 50 | 55 | | | 190 | 31 | 53 | 55 | | | | | | | | Great. | 200 | 25 | 55 | 60 | | | 260 | 22 | 60 | 50 | +-----------------+-------+-------------+--------+----------+ _Dimensions of Walls and their Counterforts, from 10 to 50 Feet high, having a Slope of ⅕ their Height._