Experiments upon Gunpowder. 1 1 



The dimensions of every part of this apparatus may- 

 be seen in the table, page 14. 



The chord of the arc through which the barrel as- 

 cended in its recoil was measured by a ribbon, and the 

 lengths of those chords, expressed in inches and decimal 

 parts of an inch, are set down in the tables. The 

 method of computing the velocity of the recoil from 

 the chord of the arc through which the barrel ascended 

 is too well known to require an explanation ; and it is 

 also well known that the velocities are to each other as 

 the chords of those arcs. The lengths of those chords, 

 therefore, as they are set down in the tables, are in all 

 cases as the velocities of the recoil. 



The powder made use of in these experiments was of 

 the best kind, such as is used in proving great guns at 

 Woolwich. A cartridge containing 12 lbs. of this 

 powder was given to me by the late General Desaguliers, 

 of the Royal Artillery, and Inspector of Brass and 

 Iron Ordnance ; who also, in the politest manner, 

 offered me every other assistance in his power, towards 

 completing the experiments I had projected, or in mak- 

 ing any others I should propose, that might be useful in 

 the prosecution of my inquiries. 



This powder was immediately taken out of the car- 

 tridge and put into glass bottles, which were previously 

 made very clean and dry ; and in these it was kept care- 

 fully sealed up till it was opened for use. When it was 

 wanted for the experiments, it was weighed out in a very 

 exact balance, with so much attention, that there could 

 not possibly be an error in any instance greater than one 

 quarter part of a grain. The bottles were never opened 

 but in fine weather, and in a room that was free from 

 damp, and no more charges of powder than were neces- 



