I. Saltpetre one hundred pound, sulphur twenty five pound, and coal twenty five pound.
II. Saltpetre one hundred pound, sulphur eighteen pound, and coal twenty pound.
III. Saltpetre one hundred pound, sulphur twelve pound, and coal fifteen pound.
IV. Saltpetre one hundred pound, sulphur twenty pound, and coal twenty four pound.
V. Saltpetre one hundred pound, sulphur fifteen pound, and coal eighteen pound.
VI. Saltpetre one hundred pound, sulphur ten pound, and coal eight pound.
Mr. Belidor, in his Hydraulics, speaks of a composition for gun powder which is as follows, to thirty pound of saltpetre, add five pound of sulphur, with as much coal: but the proportion of the several ingredients for powder, are to be found best by experience. For tho’ there has been so much practice in making powder, there has not yet been ascertained a standing proportion of the nitre, sulphur, and coal; but it is hoped that in time this great and noble invention will be much improved, and that the different, and best quantity of every ingredient, will be determined. At the powder mills they generally allow for wasting, in making up, one pound and a half in a hundred. And their mixture for a hundred weight of good powder is thus: To seventy-six pound and a half of saltpetre, well refined and dry’d, twelve pound and a half of coal, and as much sulphur, all which added together makes one hundred one pound and a half, which when worked up will nearly weigh one hundred. As it is most certain that gun-powder is capable of being improved, I shall not omit any particular that may be of service to such ingenious gentlemen as are willing to make experiments; for which reason we shall here insert another composition for powder, mentioned by an author on this subject, whose name I have forgot, but the composition is thus: Refined salt-petre five pounds, sulphur one pound four ounces, and charcoal seven ounces and a half.
But notwithstanding you may have a good proportion of ingredients, the powder will not always be the same, for there is a great deal depends on their being well incorporated, corned and dry’d, the method of which will be taught in the next article.
To restore damaged Gun-powder to its proper strength.
It is most certain, that, if powder be kept long in a damp place, it will become weak and moist, and great part of it will be formed into hard lumps, which is a certain sign of its being damaged. When powder is thus found, you will also see at the bottom of the barrel some saltpetre, which, by being wet, will separate from the sulphur and coal, and always fall to the bottom of the vessel wherein the powder is contained, and settle there in the form of a white downey matter; but the only method to prevent this, is to move the barrels as often as convenient, and place them on their opposite sides or ends, to which they before stood: but although ever so great care be taken of powder, and it be kept as dry as possible, length of time will greatly lessen its primitive strength.