384 



FIRE-ARMS 



ture bo kept clear of dirt and cinders, tho iron will bo found perfectly homogeneous 

 in every part, and there will be no appearance whatever of the seam where tho edges 



890 



came together. These tubes are repeatedly heated, and passed between the barrel 

 rolls, which are of sufficient diameter to admit of gradually decreasing grooves, the 

 whole length of tho intended barrel being indented on their surfaces. 



892 



To preserve the tubular form, and ensure regularity in the size of tho bore during 

 tho welding process, they are taken out of the furnace, by thrusting into them a tool 

 called a mandril, B,^. 893, which consists of a long rod of iron, having a short steel 



893 



treblett on its end, of tho diameter that tho bore of tho barrel is meant to bo. This 

 rod is so adjusted by means of a strong iron plate c, near its handle, which is of wood, 

 and long, that when passed with tho heated tube on it between two transverse holding 

 bars, tho short steel troblett D shall bo found exactly between tho point of impact of 

 the barrel rolls, K, B. 



The adhesion of the hot iron to the surface of I ho rolls is strong enough to draw 

 tho tube off tho mandril, which thus keeps tho boro open from end to end ; and by 

 repeating the process through tho whole scries of grooves in the rolls, tho barrel is 

 gradually elongated, and brought down to tho exact form required; an}- .supcrlluous 

 length at tho muzzle is then cut off. The breech end is then adjusted by tho hammer 



