At 100 yards a 24-pdr. ball with a charge of one-third of its weight will penetrate as follows:
| Feet. | Inches. | ||
| In | earth of old parapets, | 8 | 6 |
| “ | “ recently thrown up, | 15 | 0 |
| “ | Oak wood, sound and hard, | 4 | 6 |
| “ | Rubble stone masonry, | 1 | 10 |
| “ | Brick, | 3 | 0 |
17. What is the depth of penetration of field pieces?
Fired at the distance of 500 or 600 yards, the penetration will be from 4½ to 6 feet in parapets recently constructed, and will traverse walls of ordinary construction; but a 12-pounder is necessary to make a breach in walls of good masonry and of 4 feet in thickness, and in this case the position of the battery must be favorable, and the operation a slow one.
18. In attacking a post, or fortified position, in what manner should the fire from artillery be carried on?
Previous to an assault, the artillery ought to support the other troops by a combined fire of guns, howitzers, and small mortars, so that, if possible, the fire may be simultaneous, as such a diversity of projectiles would tend to distract the defenders and prevent them from extinguishing any fire among buildings, besides throwing them into confusion at the moment of assault. In cases of surprise, when immediate action is required, the above method cannot, of course, be practicable.
19. When firing guns of different calibres at long ranges, what are the probabilities of hitting the object?
As the squares of the diameters of their respective shot, when of equal density, and fired with proportional charges.
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