11. Velocity of a light 6 Pr.—length, 4 feet 8 inches; charge, ⅓ the weight of the shot; 1558 feet per second.—6 Prs. heavy; 6 feet 8 inches; charge ⅓ = 1673 feet.
Velocity of a light 3 Pr. length, 3 feet 4 inches, charge ⅓—1371 feet per second.
Do. Heavy 3 Pr. length, 5 feet 9½ inches, charge ⅓ the shot—1584 feet.
Hutton.
Velocity of French Ordnance.
24 Pr. charge 8 lbs. the eprovette mortar giving 125 fathoms, the initial velocity is 1425 feet per second; with the eprovette at 90 = 1209 feet; with a charge of 12 lbs. and the eprovette at 125; the initial velocity will be 1530.
| Charge. | Eprovette. | Velocity. | ||||
| 16 | Pr. | 5 lbs | 125 | 1415 | ||
| ” | ” | 8 | ” | 1510 | ||
| 12 | Pr. | 4 | ” | long guns | 1520 | |
| 8 | Pr. | 2½ | ” | 1418 | ||
| ” | ” | 3 | ” | 1460 | ||
| 4 | Pr. | 1 | ” | 1335 | ||
| ” | ” | 1½ | ” | 1508 | ||
| 12 | Pr. | 4 | ” | field guns | 1442 | |
| 8 | Pr. | 2½ | ” | 1422 | ||
| 4 | Pr. | 1½ | ” | 1446 | ||
| 8 | Inch | How’r. | 1 | ” | 390 | |
| ” | ” | ” | 1 2 oz. | ” | 516 | |
| 6 | Inch | How’r. | 1 | ” | 532 | |
| ” | ” | ” | 1 12 | ” | 704 | |
| Lombard’s Tables. | ||||||
VENT.—The vents of English guns are all ²/₁₀ of an inch diameter.—See remark 9 of the article [Velocity].
W eights—[See Measures].
WINDAGE.—The usual windage of English guns is ¹/₂₀ of the caliber. It appears by experiments, that ¼, or nearly ⅓ of the force of the powder is lost by this windage.—See remark 8 of the word [Velocity].