WINCH, (Manivelle, Fr.) The handle or lever by which a jack, windlass, &c. is turned.
WINDAGE of a gun, mortar, or howitzer. The difference between the diameter of the bore, and the diameter of the shot or shell. In England the diameter of the shot is supposed to be divided into 20 equal parts, and the diameter of the bore into 21 of those parts. The French divide the shot into 26, and the bore into 27. The Prussians divide the shot into 24, and the bore into 25. The Dutch nearly the same as the English. The general windage of shells in England is ¹⁄₄ of an inch, let them be large or small, which is contrary to all reason. It is evident, that the less windage a shot or shell has, the farther and truer it will go; and having less room to bounce from side to side, the gun will not be spoiled so soon.
It is true that some artillery officers say, that the windage of a gun should be equal to the thickness of the ladle; because, when it has been loaded for a while, the shot will not come out, without being loosened thereby, in order to unload it—and when this cannot be done, it must be fired away, and so lost: but the most advantageous windage should be in dividing the shot into 24 equal parts, and the bore into 25, on account of the convenient scale it affords, not only to construct guns thereby, but also their carriages. Hence, agreeable to this plan, the windage of a nine-pounder will be 166 of an inch, consequently a sufficient thickness for a ladle; and those of a higher calibre become still thicker in proportion: but suppose this thickness is not enough, the loss of a shot is a mere trifle, in respect to the advantage gained thereby.
Windage. The usual windage of English guns is ¹⁄₂₀ of the calibre. It appears by experiments, that ¹⁄₄, or nearly ¹⁄₃ of the force of the powder is lost by this windage. See [Velocity].
Windage of Mortars and Howitzers.
From the 13 to 5¹⁄₂ inch the windage is ·15 of an inch, and that of the 4²⁄₅ is ·2 of an inch.
Windage of Guns and Carronades.
| Kind. | 68 | 42 | 32 | 24 | 18 | 12 | 9 | 6 | 4 | 3 | 2 | 1 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Guns. | — | ·33 | ·30 | ·27 | ·25 | ·22 | ·20 | ·17 | ·15 | ·14 | ·12 | ·09 |
| Carrona. | ·15 | ·15 | ·15 | ·14 | ·12 | ·12 |
Windage of French Guns.
| Field Guns.— | All one line of windage;about ¹⁄₅₀ in an 8 pounder. | ||||
| Siege Guns.— | All 1¹⁄₂ line; about ¹⁄₄₈in a 24 Pr. | ||||
| Mortars.— | 12 | inch; | 4 | lines | of windage. |
| 10 | inch; | 1 | line, 5 points | do. | |
| 8 | inch; | 1 | line, | do. | |
| Howitzers.— | All; | 2 | lines | do. | |