the Force of Fired Gunpowder. 137 



way qualified for such an undertaking, but had been 

 present, and had assisted me in a number of similar ex- 

 periments, which I had myself made, they had acquired 

 all that readiness and dexterity in the various manipula- 

 tions which are so useful and necessary in experimental 

 inquiries ; and I think I can safely venture to say that 

 the experiments may be depended on. 



It would have afforded me great satisfaction to have 

 been able to say that the experiments were all made by 

 myself; and I had resolved to repeat them before I 

 made them public, particularly as there appear to have 

 been some very extraordinary and quite unaccountable 

 differences in the results of those made in different 

 seasons of the year ; but having hitherto been prevented 

 by ill-health, and by various avocations, from engaging 

 in these laborious researches, I have thought it right 

 not to delay any longer the publication of facts which 

 appear to me to be both new and interesting, as their 

 being known may perhaps excite others to engage in 

 their farther investigation. 



The principal objects I had in view in the following 

 set of experiments were, first, to determine the expansive 

 force of the elastic vapour generated in the combustion 

 of gunpowder, in its various states of condensation, 

 and to ascertain the ratio of its elasticity to its density : 

 and secondly, to measure, by one decisive experiment, 

 the utmost force of this fluid in its most dense state ; 

 that is to say, when the powder completely fills the space 

 in which it is fired, and in which the generated fluid is 

 confined. As these experiments were very numerous, 

 and as it will be more satisfactory to be able to see all 

 their results at one cursory view, I have brought them 

 into the form of a general table. 



