1 90 AJtneafuronent of the Strength of Gunpowder, 



III. 



Defcr'plloii and XSfc of a portable Inflrument for comparing the Force of Gunpowder. By 



Citizen RegNier *. 



I 



N procefles for the improvement of gunpowder, it is neceiTary to make comparative expe- 

 riments. Different contrivances, exliibiting various degrees of ingenuity, have been made 

 ufe of for this purpofe, which are too well known to require dcfcription in this place. I 

 {ball, therefore, only remark, that trials of gunpowder, on a large fcale, are always the beft ; 

 but as thefe experiments require apparatus and conveniences, which are not in the power of 

 every one, a fmall powder-proof has long fince been received and commonly ufed, which is 

 conftru6ted in the form of a piftol, the blaft from which drives a fmall toothed, or turned, 

 wheel, which rubs againfl: a fpring, and is moved through a greater or lefs fpace, according 

 to the force of the powder. But this machine, which is very defedlive in its refults, and can 

 be of no value when an abfolute, or at leaft approximate, indication is required of the 

 relative forces of a given meafure of powder intended for fire-arms, which are charged with 

 quantities determined in that manner. 



In fa£l, thefe proof inftruments have an arbitrary graduation. Their friction varies ac- 

 cording to the force of the fpring, and the cleannefs or oxydation of the mechanifm. 



To obviate thefe different inconveniences, I made a number of experiments, which led me 

 to a more valuable, and, in fact, a much more accurate principle; and, at length, with fome 

 modifications, I adapted a fmall brafs cannon to the fpring of the common weighing inftru- 

 ment. By this application, I immediately acquired the means of weighing the effort of the 

 blaft, and, confequently, a comparable method of eftimating its action. This machine has 

 likewife the valuable property of operating without fridtion. Its graduation is juftly deter- 



• From M^moires explicatifs du Dynamometre et autre Machines inventees par le C. Regnier. 36 Pages, 

 in Quarto, printed at Paris in the Year VII. The inftruments defcibed in this pamphlet are ; 1. The dy- 

 namometer, which, by means of apparatus conncfted with a ftrong fpring, meafures the reaftion exerted againft 

 the powers of men, horfes, and other agents, at work. 2. A fafeguard -for the priming, in mufkctry. It 

 confifts of a cylindrical piece in brafs, out of which the cavity, or pan for holding the priming, is excavated, 

 »nd another hollow cylindrical piece, which covers the firft, and is cut through in fuch manner as to prefent 

 an opening correfponding with that of the pan. When this hollow cylinder is fo difpofed, that the two open» 

 ings correfpond, the mulket may be difcharged ; but when, by turning the external part half round, the 

 pan becomes completely covered, the priming is very fecure, and the piece cannot be difcharged either by 

 accident or delign. 3. The powder-proof, which is the fubjeft of the prefent article ; and, 4. An eleflrical 

 machine. This machine operates by the friftion of a circular plate. The principal fmgularity of this ap- 

 paratus, is the conduftor, which is not cylindrical, but has the form of a flat table, with thick rounded edges 

 to prevent the efcape of the eleftric fluid. A plate of coated glafs is attached to the lower furface, which 

 anfwcrs the fame purpofes of convenience and advantage, as the jars which Nairne put into cylindrical con- 

 duftors about fixteen years ago. Eleftricians will not require that the conveniences of the flat conduftor, or 

 ^able, Should be here pointed out. N. 



mined, 



