23O ON THE WING. 



Boring and Grinding Gun-barrels. 



The boring and grinding of the barrels is the 

 process next in order, which Mr. Greener describes 

 as follows : — 



" Boring and grinding gun-barrels generally take 

 place under the same roof; the borer occupying a 

 very small shop, the grinder a large one. Two men 

 and two boys are generally found in a shop. There 

 are four benches, to each a spindle, in which there is 

 an oblong hole to receive the end of the boring bit. 

 The barrel is secured on a sort of carriage, which is 

 at liberty to traverse the whole length of the bench. 

 A boring bit is then selected of suitable size ; 

 it is put into the .spindle, and the point intro- 

 duced into the end of the barrel. A sort of lever is 

 then taken and hooked on to a kind of staple, or a 

 piece of hooked iron (a number of which are fixed in 

 one side of the bench the whole length), and passed 

 behind the carriage to force it up to the bit ; this is 

 removed and fixed again, until, by forcing up the car- 

 riage, the boring bit has passed through the whole of 

 the barrel. During this operation a stream of water 

 is kept playing on the barrel to keep it cool. A bit, 

 of larger dimensions, is next introduced and passed 

 through ; then others of still larger dimensions, until 

 the whole of the scales or blacks are entirely bored 

 out; or until the barrel has become so large in the 

 bore, as to preclude any further boring with safety. 

 If the scales are of great extent, the fault is the 

 forger's, and the loss will consequently be his. If 



