triangle will be marked, each side of which will be three and one-half
calibers long. The lower side of the triangle will be horizontal.
Three shots will be fired, the points of impact being as near as
possible the extremities of the triangle. The velocity of the shot
will be such as to give the projectile sufficient energy to just pass
through a wrought iron plate of equal thickness to the test plate, and
through its wood backing. The velocity is calculated by the Gavre
formula:

a
V² = --- { 3507 E² × 2265464 e^{1.4} }
w

[TEX: V^2 = \frac{a}{w} \{ 3507 \ E^2 \times 2265464 \ e^{1.4} \}]

V = the velocity of the projectile in feet per second.
a = the diameter of the projectile in inches.
w = the weight of the projectile in pounds.
E = the thickness of the backing in inches.
e = the thickness of the plate in inches.

Using the above formula we can make out a table as follows:

-------+-------+-------------+-------+-------+------+---------+
Plate. |Backi'g| Gun, service| w, | a, | V. | Energy, |
Inches.|Inches.| shot. |Pounds.|Inches.| f. 8.| Impact. |
| | | | | | f. tons.|
-------+-------+-------------+-------+-------+------+---------+
6 | 36 | 6" B.L.R. | 100 | 5.96 | 1389 | 1337 |
7 | 36 | 6" " | 100 | 5.96 | 1528 | 1619 |