The charcoal formerly used was made in the common way, by pits, which must have been seen by almost every one. The method is now to _distil_ the wood in cast-iron cylinders, extracting the pyroligneous acid, &c., by heating them red hot, and allowing all other volatile matter to evaporate, the charcoal only being retained in the cylinder or retorts; hence arises the name _cylinder gunpowder_. The best charcoal for sporting powders is the black dog wood; Government use willow and alder. Any charcoal does for common powders. Charcoal is ground in the same way as the nitre. Sulphur is purified simply by fusing, and when in that state, skimming off the impurities: it is cooled and pulverised in the same way as the other two ingredients. The three ingredients, after being carefully weighed in their due proportions, are sifted into a large trough, and well mixed together by the hands. They are then conveyed to the powder mill. This is a large circular trough, having a smooth iron bed, in which two millstones, secured to a horizontal axis, revolve, traversing each other, and making nine or ten revolutions in a minute. The powder is mixed with a small quantity of water put on the bed of the mill, and there kept subject to the pressure of the stones; and if we calculate the weight of the two millstones at six tons, it follows that in four or five hours’ incorporation on this bed, it subjects the ingredients to the action of full 10,000 tons. It is this long-continued grinding, compounding, and blending together of the mixture, that alone renders it useful and good. After this intimate mixing, it is conveyed away in the shape of mill-cake, and firmly pressed between plates of copper. Bramah’s press has been introduced of late years--we should say with a good deal of improvement to the powder, as will be shown hereafter--and by its means the mass is more compressed and in thinner cakes. It is then broken into small pieces with wooden mallets, and taken to the corning-house, where it is granulated, “by putting it into sieves, the bottoms of which are made of bullocks’ hides, prepared like parchment, and perforated with holes about two-tenths of an inch in diameter; from twenty to thirty of these sieves are secured to a large frame, moving on an _eccentric_ axis, or crank, of six inches throw; two pieces of lignum vitæ, six inches in diameter, and two inches or more in thickness, are placed on the broken _press-cakes_ in each sieve. The machinery being then put in rapid motion, the discs of lignum vitæ (called balls) pressing upon the powder, and striking against the sides of the sieves, force it through the apertures, in grains of various sizes, on to the floor, from whence it is removed, and again sifted through finer sieves of wire, to separate the dust and classify the grain. One man works two sieves at a time, by turning a handle and eccentric crank; the sieves being fixed to a frame, which is suspended over a bin by four ropes from the ceiling.”