Belmont Chronicle

A correspondent of the New-York Tribune in a letter from Wilmington, Delaware, gives the following interesting sketch of the process by which powder is made at the celebrated Mills of Du Pont, in that city:

"Of course of the details of the business of the Messrs. Du Pont, even if known to me I could not make mention, unless by their consent; but the process of manufacture is in reality no secret, every book of Chemistry treating of it to some extent. All know that gunpowder is composed of saltpetre, brimstone, and charcoal, though but few have any idea of the trouble and labor gone through to have these materials in a proper quality.

The saltpetre, as received at the yards, has the appearance of dirty, tainted barley, they wash it with a sort of air-blue water: by a process of refining, two or three times repeated, it assumes the appearance of snowy white crystalline salt, in which state it is fit for the powder mill. Great care is also taken to have the sulphur pure. But the most labor and trouble, though seeming to be necessary in preparing the charcoal, which is made of willow and poplar, the former being used for the best kind of powder. To ensure the success of these we can see the proprietors take any pains: in every nook on the river, trees which have been cut down even so as to leave the banks counter to the current. This method of preparing the wood gives a singular appearance to the country; for, in many places along the roads or by the stream, will be seen tall tree trunks, reaching but a little higher than a man's head, and topped out with but a fanciful branch or two. I saw whole trunks that appeared to be 40 or 50 years old, and without a limb bigger than my wrist.

The mill buildings in which the materials are ground or the mixed powder scattered along the banks of the stream, each containing a small amount. They are built of stone on three sides with heavy walls, strengthened with piers; the other side, facing the stream, is of wood, and the roof pitches toward the stream.— The plan of construction is to lessen the damage from explosions. For should an explosion take place the force would be directed toward the stream. The mills consist of two heavy iron rollers on wheels, moving in troughs. I saw one pair, each of which weighed 15,000 lbs., about seven tons. The materials, being well mixed up and pulverized in these mills, is slightly moistened, when it is pressed into cakes till it becomes almost as hard as plaster of Paris. These cakes are then broken up into small pieces and taken to the granulating mill, an operation which on account of its danger it was not permitted to see. After granulation, the powder is taken to the glazing mill. Here two or three pounds are put into a wooden cask, revolving moderately fast for twenty-four hours, there being six or eight of these casks, and cut by each were 700 pounds more, ready for another charge. From the glazing mill the powder is taken to the drying house. Here at the time of my visit, were nearly four tons of powder spread out on trays, while close by were two furnaces running away at the rate of a ton of coal each in twenty-four hours. Danger here was not, yet I could but think of Sevastopol and the story of its mines. From the drying house the powder is taken to the packing house, where it is put into barrels and canisters, and thence taken to a magazine, of which there are several, built with the same regard to minimize damage in case of explosion as the grinding mills.

While standing in one of the packing-houses, and just as I had given a kick to a hundred-pound keg of powder, intended for his excellency Santa Anna, Mr. DuPont called to a man to bring him the powder in a scoop shovel, and therein I inspected about half a peck of powder, destined to knock out of the sword some enemy of his said Excellency.

The unconcern with which this was handed me, as though it were but so much wheat, struck me as remarkable. I would not convey this idea, that carelessness is customary, or allowed, nor was the scene above mentioned a careless one; its notable feature—arising rather from my own nervousness.

On the contrary, the greatest care is exercised. The yard and the scenes being under the direct and constant supervision of some of the aid most cautious extent is the supervision carried to them. The discipline is as efficient, they hear read out orders two nights to know, than it is in the regular navy.

This with a system of liberal rewards for long and faithful service and of acts of daring bravery, in cases of casualties supposed the liability to accidents of a dangerous nature, that the property is generally safe, and a stranger visiting it is comparatively so."