constiiuent Parts of Gunpowder, 861 



Exper, 1. — 100 parts of composiiion gain from three to 

 four or five parts in weight, by the water used at the mills. 



Exper» 2. — This water appears to be totally got rid of by 

 the succeeding processes of manufacturing and stove-drying ; 

 and therefore it follows that the only aqueous matter in gun- 

 powder is what may be at first contained in the ingredients. 



Exper, 3. — The ingredients, only pulverised and mixed, 

 have a very small explosive force. 



Exper. 4. — Gunpowder granulated after having been but 

 a short time on the mill has only acquired a portion of its 

 strength. 



Exper. 5. — It is not till it has been the proper time on the 

 mill, and been properly made there, that it has obtained its 

 full powers. 



Exper. 6. — The strength of gunpowder does not depend 

 on the granulation, the dust of gunpowder after manufacture 

 having nearly the same force as when granulated. 



Exper. 7. — Powder made in every respect the same, but of 

 two sorts of charcoal, viz. pit and cylinder, is very different 

 in strength — the cylinder charcoal rendering the gunpowder 

 made therewith much superior to that made with pit charcoal. 



Exper. 8. — Powder undried, in every stage of manufactory, 

 is weaker than when dried. 



Observation, 



If the composition on a mill explodes by any accidental cause, 

 shortly after it has been put on the stones, it goes off with a 

 very slight explosive force, principally in flame ; but if it has 

 been on an hour or two under the runners, and then explodes, 

 it more or less destroys the mill, throwing the boards of the 

 covering and sides to a considerable distance. 



I shall here state a circumstance that happened, which, al- 

 though not immediately connected with the subject, may 

 serve as a strong illustration of one branch of philosophy. On 

 the explosion of the powder in a mill which had been ort 

 about two hours, the mill was wholly unroofed and the side* 

 blown out. The doors and windows of the mills on the op- 

 posite side of the stream were forced open outwards, and the 

 nails, &c. drawn. 



Vol. IX. Z z In 



