POWDEtt. 91 



With regard to the strength and other good qua- 

 lities of gunpowder, I shall, instead of saying any 

 thing farther, recommend the epreuvette (or powder- 

 proof *), whereby we can always be certain of finding 

 out the best ; provided that this machine is properly 

 made, properly used, and nicely cleaned after every 

 fire. I should observe, however, that the Uttle trifling 

 things called powder proofs, or powdertryers, which 

 sell for three or four shillings, are as likely to mis- 

 lead as to inform the person using them. 



The proper " epreuvette" is very correctly made ; 

 the wheel on which the gradations are marked is 

 large, and the spring strong ; consequently the resist- 

 ance to the force of the powder is considerable. The 

 stronger it Is the better ; for without the resistance 

 is strong, a correct proof cannot be obtained ; because, 

 if not sufficiently strong to detain the powder in the 

 chamber long enough for all the particles to ignite, 

 many of them (especially in powder of good firm 

 grain) will fly off unlnmit, and, of course, a part 

 only of the charge would be proved. 



The part, attached to the wheel of the epreuvette, 

 which shuts the mouth of the chamber, should be so 

 nicely adjusted, that on looking closely at the parts, 

 when in contact, no light can be seen between them ; 

 for, if any light, there is of course so much vacancy, 

 and consequently so much windage ; and, in propor- 

 tion to the windage, the proof will be lower ; and, 

 therefore, incorrect. 



Three fires, at least, should always be made in 



