Dee. 15, 1870 | 
NATURE 
131 

driven down by steam power, has much greater dy- 
namic force than the far heavier ones with which Krupp 
forges his steel. 
under a swift blow. 
From what has been stated, it will be understood that 
But the steel would break and crumble 
| upon Mr. Fraser's recommendation previous to his inven- 
| tion of our present system of construction, is of a soft and 
| cheap character, instead of the hard, steely iron, which is 
| much more expensive, and of which the guns were formerly 
| made. The bars for coils are made in the Royal Gun 
the wrought iron now used for our guns, which was adopted | Factories from scrap-iron, and from the stock of obsolete 


Fie. 3. 
Fic. 45 

13°9 LENGTH or BOR 

By this a very gredt economy is 
effected. Major Palliser,has in another way utilised the 
old cast-iron guns by enlarging the bore and lining it 
cast-iron ordnance. 
with a wrought-iron and steel tube. The cost of this is 
about two-thirds of a Fraser gun of the same calibre ; | 
but they cannot be equal to a gun made entirely of 
wrought-iron. 
In investigating the structure and miatevials for heavy 
| guns, we sée two great powers of nature wrestling before 
us: the strongest material and the greatest dynamic 
force, that of explosives, which man can use, and in the 
| struggle some of her more recondite laws are exhibited in 
action. Each burst gun lying in the cemetery has its epi- 
| taph (if we could read it) written by the hand of nature, 
and telling accurately the catise of death. Those few 
that havé been here deciphered and put together may 

