ON THE PENETRATION OF ARMOUR-PLATES AVITH LONG SHELLS. 



431 



against which au ogival-pointed projectile, of the service proportions, viz. 

 2^ diameters long, made of Pontypool white iron, has been fired : the pro- 

 jectile has scooped out a furrow 4 inches long and seven-tenths of an inch 

 deep ; it broke up into fragments, of which 48 were recovered. 



The plates jSTos. 1 and 3 were purposely thicker than the projectiles could 



" Whitworth " Fiat-headed Shells, 6 diameters long, containing large bursting charges. 

 No, 1. No. 2. 



No. 3. 



No. 4. 

 Flat-headed Shell, 



Nos. 1, 2, 3, and 4 were made of " Whitworth" Metal. 



quite pass through, in order that the " work" of the projectiles might be as 

 severe as possible : an examination of the projectiles themselves will show 

 how well they have withstood the severe strain to which they have been 

 subjected. The data thus obtained fidly establish, I think, the superiority I 



