_Tangent Scale._—.21 of an inch is the tangent of 1 degree to every foot of a gun’s length, from the base ring to the swell of the muzzle: Therefore if the distance in feet, between these two points be multiplied by .21, the product will be the tangent of 1 degree; from which the dispart being subtracted, will give the length of the tangent scale above the base ring for one degree of elevation for that particular gun. If the scale is to be applied to the quarter sight of the gun, of course the dispart need not be subtracted. _Tangent of 1 Degree to the following Ordnance._ +-------------------+------------+-----------+--------+ | | Length. |Tangent, 1°|Dispart.| +-------------------+------------+-----------+--------+ | |Feet. In. | Inches. | Inches.| |12 Pr. Medium | 6 6 | 1.365 | 1.475 | |12 Pr. Light | 5 — | 1.05 | 1. | | 6 Pr. Heavy | 7 — | 1.47 | 1.32 | | 6 Pr. Light | 5 — | 1.05 | 1. | | 3 Pr. Heavy | 6 — | 1.26 | 1.08 | |10 Inch Howitzer | 3 11½ | .84 | — | | 8 ” ” | 3 1 | .64 | — | | 5½ ” Light | 2 2¾ | .47 | — | | 4⅖ ” ” | 1 10 | .384 | — | +-------------------+------------+-----------+--------+ _Tangent of 1 Degree to the following French Guns._ +-------------+---------------------+---------------------+ | Nature | Siege. | Field. | | of +----------+----------+----------+----------+ | Ordnance. | Tangent | Dispart. | Tangent | Dispart. | | | of 1° | | of 1° | | +-------------+----------+----------+----------+----------+ | |In. Li. P.|In. Li. P.|In. Li. P.|In. Li. P.| |24 Pounder | 2 1 5 | 1 2 4 | — | — | |16 ” | 2 — — | 1 1 — | — | — | |12 ” | 1 10 6 | 1 — — | 1 4 — | 1 3 2 | | 8 ” | 1 8 3 | 1 — — | 1 2 — | 1 2 — | | 4 ” | — | — | 1 — — | 1 — — | | 6 In. How’r.| — | — | 0 5 6 | — | +-------------+----------+----------+----------+----------+ As the French tangent scales are marked off in inches and lines, the above dimensions are given in the same, for the more ready turning the French elevations into degrees, and thereby comparing their ranges with the English. _TENT for Laboratory Works._—Weight complete with poles, pins, &c. 3 cwt. 24 lbs. length of ridge pole, 18 feet; length of poles, 14½ feet. _Bell Tent_, now used for infantry or cavalry; weight, complete with poles, 43 lbs. length of pole, 9 feet, contain 12 men each, require 40 pegs.