involved in the Construction of Artillery. 341 



1°. Penetrative power, which, unlike that of solid cannon shot, does not depend 

 solely upon the nature of the resisting medium, the diameter and velocity of 

 the ball, but in the same medium is a function of the diameter and weight, 

 or density, and of the velocity of descent. 



2°. Explosive power, in the direct ratio of the weight of included powder. 



3°. The levelliug power, or extent of the area of demolition, a function of the ex- 

 plosive power, or of the weight of Included powder. 



4°. The fragmentary missile power, dependent upon the mass, average number, 

 and distance, to which the fragments are thrown. 



5°. The moral effect, resulting from and proportionate to, the destructive effects of 

 each explosion, and upon the degree in which it is possible to guard against 

 or to escape them. 



With spherical, similar shells, and charges, it is probable that the penetrative, explo- 

 sive, and missile powers increase, at equal velocities, with the weight of iron and of powder, 

 nearly as D* (the external diameter), within certain moderate limits ; but when the diameter 

 of the shell shall greatly exceed the largest hitherto employed, the powers upon which the 

 efficacy of the missile itself depends will be found to increase in a far higher ratio. The 

 maximum range, due to projection at equal angles, and with proportional charges of pow- 

 der, will be found also to increase with D. 



From the middle of the seventeenth century when Malthus, — an English gentleman, 

 and apparently not a soldier, — having learned the practice of throwing shells in Holland, 

 perfected the system for the French (being the first to throw them in France, at the 

 siege of La Mothe, in 1643), up to the present time, but very slight modifications appear to 

 have been made in the diameters of shells in established use throughout Europe. Borrowed 

 from the old French standard of a Paris foot in diameter, the 13-inch shell appears to be 

 about the largest employed in any service. England, Hanover, Spain, Russia, and Sweden, 

 use shells larger than those of the other European powers, and those of Russia and Sweden 

 a little exceed all the rest in. size. 



Hollow projectiles are said to have been used, on the earliest recorded occasions — at 

 Naples, 1495; at Padua, 1509; at Heilsberg, 1520; at Mezieres, 1521; at Rhodes, 1522; 

 and at Boulogne, 1542; and were made of wrought-iron, of bronze, of alloys of lead and 

 tin, and finally of cast-iron, as now. Although limited, in the seventeenth century, to the 

 existing sizes, the preceding century witnessed the use of bombs (cominges) of a very 

 much larger size. At Boulogne, as early as in 1542, shells of 19 inches, French ; at Berlin, 

 in 1683, shells of 1100 lbs. weight, existed ; at the bombardment of Genoa, in 1684, shells 

 of 1320 lbs. were thrown ; and even as late as 1745, at the siege of Tournay, the 

 French threw shells of 18 inches, weighing 550 lbs. See Valturius, " De re Militari," 

 Paris, 1534; Gentilini, " Instruttione dc Artiglicri," Venice, 1598; Biringoccio, " Piro- 

 VOL. XXIII. 2 Y 



