258 LIGHT SCIENCE FOR LEISURE HOURS. 



shot to a distance of very nearly six and a half miles. 

 Not only is this so, however, but it is well known that 

 no piece of ordnance has ever flung a projectile to so 

 great a distance since first fire-arms were invented ; and 

 it may be safely predicted that men will never be able 

 to construct a cannon which as far as range is con- 

 cerned will do much better than this one of Mr. 

 Whitworth's. The greatest range which had ever before 

 been obtained fell somewhat short of six miles. The 

 T-inch steel gun contrived by Mr. Lynall Thomas had 

 flung a* projectile weighing one hundred and seventy- 

 five pounds to a distance of ten thousand and seventy- 

 five yards ; and, according to General Lefroy's " Hand- 

 book of Artillery," that was the greatest range ever 

 recorded. But Mr. Whitworth's cannon throws a shot 

 more than a thousand yards farther. 



Yery few have any idea of the difficulties which 

 oppose themselves to the attainment of a great range 

 in artillery practice. It may seem, at first sight, the 

 simplest possible matter to obtain an increase of range. 

 Let the gun be made but strong enough to bear a suffi- 

 cient charge, and range seems to be merely a question 

 of the quantity of powder made use of. But in reality 

 the matter is much more complicated. The artillerist 

 has to contrive that the whole of the powder made use 

 of shall be burned before the shot leaves the cannon, 

 and yet that the charge shall not explode so rapidly as 

 to burst the cannon. If he used some forms of powder, 



