constituent Parts of Gunpowder, 359 



charcoal of different woods nearly alike, it is not, I believe, 

 materia! as to the, sorts of wood made use of. 



The several ingredients being thus prepared, are ready for 

 manufacturing. They are, 1st, separately ground to a fine 

 powder : 2d, mixed together in the proper proportions : 3d, 

 the composition is then sent to the gunpowder-mill, which 

 consists of two stones vertically placed, and running on a bed- 

 stone. On this bed-stone the composition is spread, and 

 wetted (hot with sal-ammoniac, urine, &c. as some authors 

 state, but) with as small a quantity of water as will, together 

 with the revolutions and weight of the runners, bring it into 

 a proper body, but not into a paste. After the stone runners 

 have made the proper number of revolutions over it, and it is 

 in a fit state, it is taken off. 



A powder-mill is ,a slight wooden building and boarded 

 roof. Only about 40 or 501b. of composition is worked here 

 at a time, as an explosion will sometimes happen from the 

 runners and bed-stone coming in contact, and other causes. 

 These mills are either worked by water or by horses. 



4th, The composition taken from the mills is sent to the 

 coming-house to be corned or grained. Here it is first passed 

 into a hard and firm body, broken into small lumps, and the 

 powder then grained, by these lumps being put into sieves, 

 in each of which is a flat circular piece of lignum vitss. The 

 sieves are made of parchment-skins, having round holes 

 punched through them. Several of these sieves are fixed in 

 a frame, which by proper machinery has such a motion given 

 to it, as to make the lignum vitse runner in each sieve go 

 round with a quick velocity, breaking the lumps of powder, 

 and forcing them through the sieves, forming grains of several 

 sizes. The grains are then separated from the dust by proper 

 sieves and reels, 



5th, They are then hardened, and the rougher edges taken 

 off by being rmi a sufficient length of time in a close reel, 

 having a proper circular velocity given it. 



The powder for guns, mortars, and small arms is gene- 

 rally made at one time, and 'always of the same composition. 

 7'he difference is only in the size of the grains, which are 

 separated by the sieves of different fineness, 



6th, 



