+--------------------------------++-----------------------------+ | Wall. || Counterforts. | +--------+-----------+-----------++--------+---------+----------+ | | | ||Distance| | | | | Thickness |Thickness ||between | | | |Height. | at Top. |at Bottom. || them. | Breadth.| Length. | +--------+-----------+-----------++--------+---------+----------+ |Feet. |Feet. Inch.|Feet. Inch.|| Feet. |Feet. In.| Feet. In.| |10 | 4 0 | 6 0 || 8 | 2 8 | 4 — | |15 | 4 3 | 7 3 || 10 | 3 4 | 5 — | |20 | 4 6 | 8 6 || 12 | 4 0 | 6 — | |25 | 4 9 | 9 9 || 14 | 4 8 | 7 — | |30 | 5 0 | 11 0 || 16 | 5 4 | 8 — | |35 | 5 3 | 12 3 || 18 | 6 0 | 9 — | |40 | 5 6 | 13 6 || 20 | 6 8 | 10 — | |45 | 5 9 | 14 9 || 22 | 7 4 | 11 — | |50 | 6 0 | 16 0 || 24 | 8 0 | 12 — | +--------+-----------+-----------++--------+---------+----------+ The heights in the above table are taken only from the bottom of the ditch, and do not include the foundations. When the rampart is partly walled and partly turfed; then ⅕ of the height of the turfed part must be added to the breadth of the wall at the top given in the table. The bases of all inward slopes of earth should be equal to their height, if not more. The bases of all outward slopes of earth ⅔ of their height. The superior slopes of all parapets ⅙ of their breadth. The slope of all walls, or revetement ⅕ of their height. Though the above principles given for the erection of field works may assist an officer’s recollection who may be employed on that duty, the memorandums given respecting _permanent_ fortification pretend to no such object: but may serve to remind an officer, if he should visit a fortification, of its essential requisites; and may assist his observations in passing round the works. _FUZES.—Composition._ Saltpetre 3 lbs. 4 oz. Sulphur 1 — Mealed powder 2 12