388 lewis' AMERICAN SPORTSMAN. 



instrument in common use in England, but scarcely known 

 in this country, and on this account important that Ave should 

 speak of it in this place. 



The Epreuvette, though the most perfect of all instruments 

 yet invented for the purpose of testing the strength of gunpow- 

 der, if not used properly, will often give very unsatisfactory 

 results. The construction of the Epreuvette should be perfect 

 in all its parts, more particularly in the spring which controls 

 the movements of the Avhcel on which the gradations are 

 marked. The mouth-piece, or rather the piece which closes 

 the muzzle of the Epreuvette and is attached to the grading- 

 wheel, should fit closely in its place, so as not to allow any 

 space to be seen between the two surfaces when held up to the 

 light. 



One trial is not sufficient to test the quality of the powder ; it 

 will be better to make several, and then take the average of the 

 whole. The chamber should be nicely cleaned after each fire, 

 provided we wish to obtain a close analysis. 



rOWDER PRESERVED FROM MOISTURE. 



Powder should be kept dry and never exposed to a humid 

 atmosphere, as it has a great tendency to imbibe moisture, and 

 will soon become unfit for service. If by any mishap it should 

 become damp, it can be dried before the fii^e, or in the sun on a 

 metal dish — a coal fire is the proper kind of fire to dry it be- 

 fore ; a wood fire is rather dangerous, owing to the chance of 

 sparks flying out, as they most frequently do, more particularly 

 if the wood be wet or gre6n. We have dried our powder more 

 than once by putting the dish which contained it on top of a 

 brick placed on a stove. 



The fact of the tendency of powder to absorb moisture may 

 be very fairly and satisfiictorily demonstrated by accurately 

 weighing a certain proportion of this article, and placing it in a 

 damp situation for a few hours, when it will be found that it has 

 increased very perceptibly in weight, owing to the absorption 

 of the damp, or rather the moisture. The projectile force of 

 powder is considerably diminished by dampness, because its 

 combustion being much slower, a large proportion must neces- 



