CHAPTER I.

OF THE LABORATORY.

The laboratory for pyrotechny may consist of a building, furnished with furnaces, boilers, &c. for the preparation or refining of saltpetre, and other substances for use; but according to its present acceptation, it is a place where all kinds of fire-works are prepared, both for actual service and for exhibition; such as, besides the ordinary works for show, quick matches, fuses, port-fire, grape-shot, case-shot, carcasses, hand granades, cartridges, &c. It should have tables, benches, and closets, where the tools, paper, thread, &c. may be commodiously placed, and an adjoining room to contain a supply of materials for two days' work.

The chief artificer takes the weight of the materials made use of, attends to the weighing of the different substances, and sees that the mixtures are made properly, &c. He also keeps an account of the number and kinds of fire-works. The prepared fire-works ought to be removed daily to the magazine. If they are made up in the field, under a tent, (denominated the _Laboratory tent_,) they should be packed in barrels or in caissons.

_Sec. I. Of Laboratory Tools and Utensils._

The following constitute the furniture and equipments of a laboratory:

Copper rods, to load port fires, and the fuses of shells, howitzers, &c. Wooden formers, on which to roll the paper cases of the port fires. Wooden formers, to roll the cases of rockets. Balances, large and small, with weights, &c. Buckets to carry water. Boxes for loading priming tubes. Barrels with leather tops, that draw, in order to keep grained and meal gunpowder. Rods, or rammers for charging rockets. Brushes to wipe the tables and sweep the compositions together. Frames to dry priming tubes. Copper calibers to regulate the size of priming tubes. Penknives. Needles for piercing priming tubes in the direction of their length. Fuse drivers. Coopers' adzes. A copper kettle. Scissors for cloth and paper. Paper cutters. Priming wires. Skimmers for skimming the froth of boiling saltpetre. Funnels for charging port-fires, howitzers, shells, &c. Square ruler. Fuses for shells, &c. (or a lathe to make them.) Large and small wooden bowls. Small axes. Ladles for charging the fuses of shells, port-fires, &c. Mallets to hammer the fuses. Glue pots and brushes. Heavy mallets to beat the powder. Tin measures, of different sizes. Hand mortar. Foot rules. Rat-tail files to cleanse the interior of the reeds of priming tubes. Wooden rasps. Iron rulers, 1/2 foot long. Leather bags, in which gunpowder and charcoal are reduced to powder. Pocket saws. Pallet knives for saltpetre. Tables, small ones to mix the composition; large ones with a ledge to meal the powder on. Sieves, fine and common; of silk, and of hair. Fuse drawers. Tools for rolling cartridges. Gimblets of different sizes.

The materials required more particularly for military fire-works, are:

Gunpowder. Saltpetre. Sulphur. Charcoal. Camphor. Beeswax. Glue, rosin. Cotton yarn for quick match. Brandy or other spirits. Gum arabic. Linseed oil. Spirits of turpentine. Pitch. Reeds or quills for priming fuses. Mutton tallow. Vinegar. Thread for tying quick match. Cartridge paper. Thread, tow and spun yarn, to make match rope. Cordage, to make tourteaux. Flour to make paste.

The characters used to express certain substances employed in fire-works, are the following: (_James's Mil. Dict._ p. 101.)

M. means meal powder, ⊝. Saltpetre. C. Z. Crude sulphur. C. S. Sea coal. S. x Steel or iron filings. G. x Glass dust. C. I. Cast iron. X. Camphor. B. L. Lampblack. L. S. Lapis Calaminaris. W. Spirits of wine. P. O. Oil of spike. ∋. Corn powder. Z. Brimstone. C. + Charcoal. B. R. Beech raspings. B. x Brass dust. T. x Tanners' dust. C. A. Crude antimony. A. Y. Yellow amber. G. I. Isinglass. ⩀. Gum. S. T. Spirits of turpentine.

_Sec. II. Of Mandrils and Cylinders for forming Cartridges and Cases._

The rollers or rods, on which cartridges are formed, ought to be solid, and perfectly straight and round. Very dry, sound wood should be selected, and when turned, the rod should be perfectly cylindrical; one extremity being concave, and the other convex.

Mandrils may be made of copper, which is preferable to wood, as this is apt to warp and crack; and in both cases, should be longer than the cartridge, so as to be drawn out easily. They are of different lengths and diameters, according to their respective uses.

_Sec. III. Of Rammers, Chargers, and Mallets._

The rammers which are used for compression, are cylindrical like the preceding. They have a head much larger in dimensions than the part that enters the tube. (See A, B, C, D, and E of Fig. 1. in the Plate). Besides being made of wood, which should be of the hardest kind, as _lignum vitæ_, they may be formed of copper or brass. In this case, they are first cast of the requisite size and shape, and finished in a lathe. Wooden heads are sometimes put to them, but with little advantage; as they frequently split and require to be renewed.

The wooden rammer may be struck with metal; but when the rammer is of copper or brass, wooden mallets must be always employed.

We may here remark, that in charging rockets, it has been customary to employ several rammers. The first _drift_ must be six diameters from the handle, and this, as well as all other rammers, ought to be a little thinner than the former, to prevent the tearing of the paper, when the charge is driven in. In the end of this rammer is a hole to fit over the piercer. (See B. Fig. 1.) The line marked on this rammer, as will be explained hereafter, when it appears at the top of the case, indicates that a second rammer must be used. This second rammer, from the handle, is four diameters, having a hole for the piercer, 1-1/2 diameters long. (C. Fig. 1.) When the case is filled as high as the top of the piercer, a short and solid drift is used. (E. Fig. 1.).

Rammers must have a ferrule, or collar of brass at the bottom, to keep the wood from spreading, or splitting. With regard to the handles of the rammers, if their diameter be equal to the bore of the mould, and two diameters long, the proportion is a good one. The shorter they can be used, the better. The longer the drift, the less of course, will be the pressure on the composition, by the blow given by the mallet.

We may observe here, that rockets may either be driven over a piercer, or driven solid, and afterwards bored.

As much of the effect of rockets depends upon the manner they are driven, whether lightly or compactly, or uniformly throughout, circumstances which affect their quality; it is necessary, in using the rammer, to employ an equal force for driving the composition. The mallet, therefore, should be of a given weight; and a certain number of strokes with the same force, on each new charge, must be accurately followed, until the driving is completed; taking care, at the same time, that the rocket stands firm on a solid body.

Dry beech is the best wood for mallets. A writer very judiciously observes, in the _Encyclopedia Britannica_, (vol. xv, 695), that, if a person uses a mallet of a moderate size, in proportion to the rocket, according to his judgment, and if the rocket succeeds, he may depend on the rest, by _using the same mallet_; yet it will be necessary, that cases of different sorts, be driven with mallets of different sizes. In all cases, under one ounce, the charge may be rammed with an ounce mallet.

There is an advantage, also, by having the handle of the mallet turned out of the same piece as the head, and made in a cylindrical form. If their dimensions are regulated by the diameters of the rockets; then, for example, if the thickness of the head be three diameters, and its length four, the length of the handle will be five diameters, whose thickness must be in proportion to the hand.

Bigot (_Artifice de Guerre_, p. 118) speaking of the flying fuses, or sky-rockets, observes, that the mallet used for driving the composition, is proportionably large, according to the rockets, and that it is five inches in length, and four in breadth, when the diameter of the rocket is from 12 to 18 lines. The mallets for larger rockets are stronger and heavier, and, in some instances, where a great force is required, as in driving war-rockets, a machine similar to the pile-engine, is used. See _Congreve Rockets_.

_Sec. IV. Of Utensils necessary for constructing of Signal Rockets._

A detailed account of the tools used in making signal rockets, may be seen in Ruggeri, _Pyrotechny_, p. 143; but M. Bigot has enumerated them as follows:

One mandril for forming the cartridge, or case. One pair of curved compasses to determine the exterior diameter. Three conical mandrils. (See fig. 3, plate.) One solid, or massive cylinder. One mould for garnishing. Two moulds for the capitals, or heads, one of which is for the rockets with, and the other for the rockets without, the _garnish_, or furniture. One piercer and block (See plate, fig. 1, I & H.) One scoop. One punch. One mallet. One press. One large knife. One pair of scissors.

All the wooden utensils ought to be made of hard and sound wood, without knots. The rammers should be furnished with rings or ferrules, and the first bored with a hole of sufficient length to receive the piercer. The second should be bored deep enough to receive two-thirds of the piercer, and the third, to receive one-third, while the fourth should be solid. These rammers are all furnished with heads. (See section iii.)

_Sec. V. Of the Rolling, or Plane Board._

This board is furnished with a handle, and is used for rolling rocket cases, &c. and is of different dimensions, according to its application. It is made of hard wood, such as oak or walnut.

When the paper is wrapped round the mandril or _former_, the rolling board is used to compress the paper, and make it round and smooth.

_Sec. VI. Of the Driver for charging large Rockets._

This contrivance is similar to a pile driver in construction; and, by means of a weight falling upon the rammer, the charge is sent home with great force. Its use is confined to the largest kind of rockets.

_Sec. VII. Of Mortars and Pestles._

Mortars are employed for the pulverization of substances, and, according to their use, may be either of wood, marble, brass, or cast-iron, which last costs less than the others. Large mortars have covers, in order to confine the finer particles. The pestles should be of very hard wood; because, in that case, no danger would be apprehended of an explosion of the materials, an occurrence which might take place, if iron were used. This, however, depends on the substances submitted to the pestle.

_Sec. VIII. Of the Choaker or Strangler._

The choaker is nothing more than a contrivance, usually made of rope, by which the closing of the end of the rocket is effected, so as to form a kind of cup or mouth.

_Sec. IX. Of the Table and Sack for mealing Gunpowder._

This table may be either square or an octagon, and made of hard wood. There is a rim, a few inches high, raised round it, and a gutter at one end to allow the powder to pass out, when the operation is finished. See plate, fig. 7 and 8.

This mode of mealing powder is by no means to be preferred. (See _Gunpowder_.)

A sack is also used for crushing powder. It should be made of strong elastic leather, and sewed together in such a manner as to prevent the impalpable powder from passing through its seams. They are of an oblong shape, and contain from 20 to 25 pounds. Fifteen pounds are generally put in at a time. This method of crushing powder is preferred, as it is less liable to accidents. It is hardly necessary to add, that the bag is beaten with a cylindrical stick.

_Sec. X. Of Sieves._

There are several kinds of sieve. The common sieve has neither a cover nor a receiver, and may be either formed of horse hair, or of brass or copper wire. It is necessary to have some sieves of a finer kind. For this purpose, silk and gauze are generally used. The cover is merely leather, fixed in a frame, which fits on the top. The receiver is formed nearly in the same manner, having a skin stretched over a frame, which fits on the under part of the sieve.

_Sec. XI. Of the Paper Press._

A press, for the purpose of pressing paper, is formed of two pieces of wood, which are brought together by means of one, or several screws. This press is sometimes, though seldom, used. If pasteboard is made, when it cannot be had ready prepared, then the press is actually necessary. The intention is to unite the several sheets, which have been pasted, by using the pressure of the screw, and to remove any extraneous paste, so that the paper may have no inequalities on its surface. In lieu of the screw-press, heavy weights laid on the paper for several hours, will answer the same purpose.