MISCELLANEOUS HINTS. 445 



expansive force of the powder acts with increased vigor upon these 

 weak points, owing to the resistance it meets with from the stronger 

 portions of the tube. 



If the subtle fluid generated by the inflammation of gunpowder 

 be suddenly compressed or checked by a contraction in the calibre 

 of the barrel, an undue proportion of the expansive force is exerted 

 upon this point, and the result may be the bursting of the instru- 

 ment. This fact will of itself show the folly of attempting to increase 

 the shooting-powers of the gun by unequal boring of the barrel, or 

 rather the contracting of the diameter of the calibre at some given 

 point in its length, as has been practised by some ignorant gun- 

 smiths. We cannot imagine any cause better calculated to burst 

 a fowling-piece than the contraction of its regular calibre from 

 this erroneous method of boring, and would rather trust ourselves 

 with a straight-bored barrel made of far inferior metal, than with 

 one of these ill-shapen instruments forged of the very best stub- 

 and-twist. If the muzzle of the gun becomes stopped up with dirt 

 or snow while in the act of springing over a ditch, or from a fall, 

 and the extraneous matter should be of a consistency sufficiently 

 hard to offer any considerable degree of resistance to the expulsive 

 force of the powder, the barrel will be bursted without fail near its 

 mouth ; and the same accident will more readily occur if the mouth 

 of the piece be sunk a few inches below the surface of the water, as 

 the resistance offered by this fluid to the passage of the load under 

 such circumstances is far more powerful than that presented by the 

 thin sides of the barrel, and the weaker antagonism must necessarily 

 give way to the stronger. That a gun will burst very readily if the 

 muzzle be sunk a few inches under the water, we have not the least 

 doubt ; and an accident which happened to an acquaintance of ours, 

 some years since, confirms us in the opinion. 



A fowling-piece may also burst from bad loading; we do not 

 mean entirely from overcharging, but sometimes from the want of 

 proper precaution in ramming down the shot on the powder, or the 

 moving of the wad of one barrel by the jar communicated to it by 

 the explosion of the other. Bursting from this latter cause is 



