222 VARIETIES OF SHOT-GUNS, ETC. 



carriage for the barrel to travel in, and is exactly similar in 

 principle to a turner's lathe. The boring bit, being selected 

 of a proper size, is placed in the centre of the spindle, ready 

 to revolve as soon as the latter is set in motion ; the barrel 

 is then fixed in its carriage, so that it may gradually be 

 pushed on upon the bit as the latter clears its way, and then 

 the spindle is made to revolve by attaching its driving-wheel 

 to the motive force, whether hand or steam. The bit is 

 square for about twelve or fourteen inches, with four angles, 

 two of which are ground sharp, while the other two in the 

 finishing operation are kept from the interior of the barrel 

 by a slip of wood, which diminishes the friction considerably. 

 Water is constantly poured upon the barrel as the work 

 goes on to keep it cool, and when the bit has cleared its way 

 through, another, slightly larger in size, is introduced, till the 

 barrel is of a proper bore. When the interior is finished it 

 bears a fine polish, but it is a mere cylinder, and will still 

 require some slight modification to make it shoot correctly ; 

 but this is generally done by a hand bit. Next comes the 

 grinding of the exterior, which is either done by means of 

 large stones made to revolve with great velocity, and against 

 which the workman holds the barrel, allowing it at the same 

 time to turn round comparatively slowly in the hand j or a 

 self-acting lathe is made to take the part of man and stone, 

 and any number of barrels are then turned out exactly 

 similar to each other in every respect but in the metal itself, 

 which of course may and will vary slightly. The method by 

 turning is the more true, but if care is not taken to keep the 

 machinery in perfect order the tool is apt to tear up the 

 surface and overheat the metal, which can be more com- 

 pletely avoided by the grindstone. 



When the barrels are thus bored and ground, they have 

 still to be put together if for a double-barrelled gun, and in 

 any case to be breeched, cut to a proper length, and finally 

 bored for shooting. In the first of these operations, con- 

 siderable nicety is required in order to direct both barrels 

 at the same object. It must be remembered that the 

 breech-end is much thicker than the muzzle, and consequently 

 in placing together two barrels as they come from the stone 

 or lathe, if the two external surfaces touch at both ends, the 



