If the weight should be expressed by a fraction, the rule is still the same: for instance, the diameter of a 1¹⁄₂ pound ball, or ³⁄₂, is found by adding the logarithm .2839793, found above, to .0586971 ¹⁄₃ of the logarithm of ²⁄₃, the sum .3426764 will be the logarithm of the diameter required, i. e. 2.2013 inches.
As the diameter of the bore, or the calibre of the piece, is made ¹⁄₂₀ part larger than that of the shot, according to the present practice, the following table is computed for this proportion.
Diameters of the shots and calibres of English guns.
| lb. | 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | 1.923 | 2.423 | 2.775 | 3.053 | 3.288 | 3.498 | 3.679 | 3.846 | 4.000 | diam. |
| 0 | 2.019 | 2.544 | 2.913 | 3.204 | 3.568 | 3.668 | 3.861 | 4.038 | 4.200 | calib. | |
| 1 | 4.143 | 4.277 | 4.403 | 4.522 | 4.635 | 4.743 | 4.846 | 4.945 | 5.040 | 5.131 | diam. |
| 4.349 | 4.490 | 4.623 | 4.748 | 4.866 | 4.981 | 5.088 | 5.192 | 5.292 | 5.368 | calib. | |
| 2 | 5.220 | 5.305 | 5.388 | 5.409 | 5.547 | 5.623 | 5.697 | 5.769 | 5.839 | 5.908 | diam. |
| 5.480 | 5.579 | 5.661 | 5.742 | 5.824 | 5.893 | 5.982 | 6.057 | 6.129 | 6.203 | calib. | |
| 3 | 5.975 | 6.041 | 6.105 | 6.168 | 6.230 | 6.290 | 6.350 | 6.408 | 6.465 | 6.521 | diam. |
| 6.275 | 6.343 | 6.410 | 6.475 | 6.?41 | 6.604 | 6.666 | 6.707 | 6.788 | 6.846 | calib. | |
| 4 | 6.576 | 6.631 | 6.684 | 6.737 | 6.789 | 6.640 | 6.890 | 6.940 | 6.989 | 7.037 | diam. |
| 6.904 | 6.962 | 7.018 | 7.076 | 7.128 | 7.182 | 7.234 | 7.287 | 7.338 | 7.383 | calib. |
EXPLANATION.
The numbers in the first line of the table are units, and those in the first column of the left side of the table tens; the other numbers, under the one, and opposite to the others, are the respective diameters of shot and calibres. Thus, to find the diameter of the shot, and the calibre of a 24 pr. look for the number 2 on the left-hand side, and for 4 at top; then the number 5.547, under 4, and opposite 2, will be the diameter of the shot in inches and decimals, and the number 5.824, under the first, the calibre of a 24-pounder &c.
Diameters of the Bullets and Calibres of English musquets.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | |
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 0 | 1.671 | 1.326 | 1.158 | 1.05 | .977 | .919 | .873 | .835 | .803 |
| 1 | .715 | .?51 | .730 | .711 | .693 | .677 | .663 | .650 | .637 | .626 |
| 2 | .615 | .605 | .596 | .587 | .579 | .571 | .564 | .557 | .550 | .544 |
| 3 | .538 | .536 | .526 | .521 | .517 | .511 | .506 | .501 | .497 | .493 |
The diameter of musquet bores differs about ¹⁄₅₀th part from that of the bullet.
Diameter of powder measures. See [Powder Measures].