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POPULAR SCIENCE MONTHLY. 



The cost of a single discharge thus exceeds five hundred dollars. 

 But this is not all. So great is the wear and tear of each dis- 

 charge upon the 

 bore that after two 

 hundred and fifty 

 rounds the gun be- 

 comes unfit for fur- 



o^ ER H / ther use until it is 



relined by the in- 

 sertion of a new 

 rifled tube within 

 the original i tube, 

 the old rifling hav- 

 ing been removed. 

 The gun will then 

 stand two hundred 

 and fifty more 

 rounds. Assuming 

 six hundred rounds 

 for the entire life 

 of the gun, each 

 round thus costs 

 one hundred dol- 

 lars in wear and 

 tear, in addition to 

 the five hundred 

 dollars' worth of 

 material used in 

 loading. Such a 

 gun as this is but 

 a single small ele- 

 ment in the cost 

 of a modern war. 



Several of them, besides a number of smaller guns, are usually 

 placed on every large armor-clad battle ship. The cost of this 

 with its equipment mounts up into millions of dollars. Neverthe- 

 less, it has been necessary to coin into our language the word 

 " jingo," to designate the bragging noncombatant who clamors 

 for war because of the fancied stimulus which it is supposed to 

 give to patriotism and prosperity. On comparing this gun with 

 the largest Parrot t rifle of thirty years ago we see that its length 

 is more than three times, its weight nearly five times, and its cost 

 thirteen times as great. For the cast-iron Parrott gun the charge 

 of powder weighed about one tenth as much as the projectile. 

 For the modern steel gun this ratio is raised to one half, with 

 corresponding increase of destructive energy. 



SECTIONAL DIAGRAM, showing compression of tube and extension 

 of hoops after assemblage of the component parts of a gun. 



