APPENDIX B.—No. I.
GRADUATION OF SIGHTS AND MEAN RANGES
OF
UNITED STATES NAVAL SMOOTH-BORE GUNS.
(From Results of Practice, by Admiral DAHLGREN, United States Navy.)
The graduation commences from the bottom of the head of the bar resting on the sight-box.
The aim is supposed to be taken at the water-line of a ship.
| 32-Pounder of 27 cwt. | 32-Pounder of 33 cwt. | ||||
| Charge | 4 lbs. | 4 1/2 lbs. | |||
| Axis of bore above load-line | 7 feet. | 7 1/2 feet. | |||
| Distance between sights | Old Model. 29 1/4 inches. | New Model. 26 3/4 inches. | 31 inches. | ||
| Elevation. | Range. | Graduation. | Graduation. | Range. | Graduation. |
| Degrees. | Yards. | Inches. | Inches. | Yards. | Inches. |
| Level. | 250 | 0.353 | 0.324 | 287 | 0.350 |
| 1° | 545 | 0.746 | 0.684 | 581 | 0.792 |
| 2° | 800 | 1.266 | 1.161 | 857 | 1.343 |
| 3° | 1,047 | 1.801 | 1.652 | 1,140 | 1.909 |
| 4° | 1,278 | 2.337 | 2.144 | 1,398 | 2.478 |
| 5° | 1,469 | 2.870 | 2.633 | 1,598 | 3.044 |
| 6° | 1,637 | 3.398 | 3.116 | ... | ... |