234 ON THE WING. 



direct quantity of space on the face of the breech 

 receives the same impulse as the ball projected, and 

 is acted upon in precisely the same ratio in proportion 

 to their different weights. In a musket of n Ibs., 

 the comparative weight of gun and ball is as i to 

 176 ; and exactly in that proportion will be the dis- 

 tribution of impulse from the expellent fluid. It thus 

 becomes a plain question between the patent breech 

 and the flat surface of the plug. The two halves of a 

 parabola inverted, or the shape of a parabolic spindle, 

 will be the best shape, according to the laws of science. 

 The representation given on page 234 is as near as I 

 can get the engraver to represent my views of the 

 best shape of breech." 



LAMINATED STEEL BARRELS. 



With reference to laminated steel barrels, Mr. 

 Greener says : 



" There are six qualities or varieties of mixtures of 

 iron for barrels of best quality. The plate-facing 

 contains two kinds finished, composed of steel en- 

 tirely, but of, different degrees of carbonization : one 

 is composed entirely of a laminated series containing 

 many scores of distinct laminae in the thickness of the 

 sides of the barrels, twisted and beat into tortuous 

 shapes ; the other, of larger laminae, but showing 

 the edges of the laminae at an angle with the length, 

 and thus appearing larger than if presenting the side 

 or end of the plates. 



" Care must be taken that the great proportion of the 



