For flying saucissons, the French make use of cases of three-quarters of an inch in exterior diameter. They are charged, to the height of half an inch, with the composition for mosaic tourbillons, which see. They are then choaked and bound at this place, and four fingers of grain powder are put into each, which is then covered with a stopper of paper. They are then again choaked and bound, and the excess of the case is cut off. They are primed with a piece of match, using the priming paste at the same time. When the saucissons are required to make a louder report, the part of the case, in which the powder is, should be wrapped round with pack-thread, much in the same manner as already described, and then covered with glue or pitch. These saucissons are usually put in the pots of the mosaics, some times in the place of them, and are arranged for exhibition on the same frame. We may, if we wish to vary the effect, put a saucisson in one pot, and a mosaic in another. When thrown in the air, their effect is to occasion a report. They first, however, form a tail of fire, and finish with an explosion. Bigot gives the difference between their internal and external diameters at four lines, or one-third of an inch.

Saucissons may either be used in the manner we have mentioned or thrown by hand. According to their size, and the strength of the case, so will be the report. They resemble a thick and short sausage, hence their name.

Sec. XXVI. Of Fire-Pumps.

Fire-pumps are intended for a particular use, which we will describe hereafter. The composition is the following:

1.Saltpetre,5lbs.
Sulphur,1—
Meal powder,1½—
Glass-dust,1—
2.Saltpetre,5lbs.8oz.
Sulphur,2—
Meal powder,1—8—
Glass-dust,1—8—

Cases for fire-pumps are made like those for tourbillons, except that they are pasted, instead of being rolled dry. In charging them, first put in a little meal powder, and then a star; then a ladleful or two of the above composition, which ram tightly; then a little meal powder, on that a star, and then composition again, and so on until the case is filled. Stars for fire-pumps should not be round; but must be made either square, or flat and circular, with a hole through the middle. The quantity of powder for throwing the stars must increase as we come near the top of the case; for, if much powder be put at the bottom, it will burst the case. The stars must differ in size in this manner: Let the star, which is first put in, be about one-fourth less than the caliber of the case; but let the next star be a little larger, and the third star a little larger than the second, and so on for the rest. Let them increase in diameter till within two of the top of the case, which two must fit in tight. As the loading of fire-pumps requires some skill, it will be necessary to make two or three trials before depending on their performance.

When a number of pumps are filled, care must be taken not to put in each an equal quantity of charge between the stars; so that, when they are fired, they may not throw up too many stars together. Cases for fire-pumps should be made very strong, and rolled on four or eight-ounce formers, each ten or twelve inches long. For the composition and preparation of stars, see stars.

Sec. XXVII. Of the Volcano of Lemery.

The artificial earthquake, or volcano of Lemery, is formed by mixing into a paste with water, about equal parts of sulphur and steel or iron filings, and burying the mixture in the earth. The composition in a short time, will grow hot, and burst out; the earth will break, and open in several places.

Baumé mixed 100 pounds of iron filings and the same quantity of sulphur together, with water, and rammed the mixture into an iron pot. After ten hours, the mass swelled up and grew warm, aqueous vapours arose, and the mass burst. Ten hours afterwards, the heat, vapours, &c. greatly increased, and a flame issued forth, lasting only from 2 to 3 minutes. Finally, the mass became red-hot, and the burning and heat continued 40 hours longer; but without flame.

We may merely remark, that this effect is produced by the chemical union, which takes place between the sulphur and iron, forming a sulphuret of iron, analogous in composition to the native martial pyrites. The water is at the same time, decomposed, during which the mixture swells, becomes hot, and throws up the earth, producing at the same time a large quantity of sulphuretted hydrogen gas. This gas is formed by the combination of a part of the sulphur with the hydrogen of the water; whilst the oxygen, the other element of the water, goes to oxidize the metal and to acidify the remaining sulphur. Hence sulphate of iron, or green vitriol is produced. The experiment may be made in a common basin.

It is a remarkable fact, that spontaneous combustion, which takes place without the application of an ignited body, ensues in a variety of instances; and new facts daily occur, which show, that cases of this kind are more numerous than we had reason to suspect. Besides the old and well known effect of quicklime, pyrites, pyritous schist, &c. in producing spontaneous combustion, it is found, that ashes and oil, oil and cotton, and a number of substances have set fire to cotton mills, and other works.

It is known, that, in the slaking of quicklime, a considerable degree of heat is produced. This is owing to the solidification of the water, or its union with the lime in the form of a hydrate, and the consequent change, which the caloric undergoes from a latent to an uncombined state. Hence inflammable substances, in contact with lime, under these circumstances, are necessarily set on fire.

Spontaneous combustion arises simply from a play of chemical affinities. The following general observations on this subject are given by Nicholson, (Chemical Dictionary); and an enumeration of the effects may lead to cautions of importance for preventing serious accidents: "If quicklime, in any quantity, be laid in contact with any combustible, as wood, and be wetted by accident, or to make it into mortar, a sufficient quantity of heat may be extricated to set fire to the wood. Animal or vegetable substances, laid together damp in large heaps, undergo a fermentation, which often excites combustion, as in the case of hay-ricks. Woollen cloth, not freed from the oil used in dressing it, and laid up damp in large heaps, has been known to take fire; and so has painted canvass. Flowers and herbs boiled in oil, as is done by druggists, and then laid in heaps, sometimes do the same. The mixture of linseed oil and lampblack, or of linseed oil and black wad, is very liable to inflame. Torrefied vegetables, as malt, coffee, or bran, put while hot, into coarse bags, are apt to take fire. The spontaneous combustion of phosphorus, and various pyrophori, is well known. It is suspected to be owing to the presence of one or other of these, that charcoal sometimes takes fire without any apparent cause; and the charcoal of peat is said to be particularly liable to this. Hyperoxygenated muriate of potassa, mixed with sulphur, or with sulphur and charcoal, is apt to detonate spontaneously.

"Many cases of spontaneous combustion taking place in the human body too are on record: and it has been observed, that all the persons, who thus suffered, were much addicted to the use of spirituous liquors."

Sec. XXVIII. Of the blue and green Match, for Cyphers Devices, and Decorations.

We had occasion to mention, that blue and green flame may be produced by employing sundry substances, which have the property of changing the colour of flame. This is effected in the present instance.

For the preparation of the match, we melt one pound of roll brimstone in a glazed earthen vessel, over a slow fire, and add one ounce of finely pulverized verdigris, and half an ounce of antimony. The cotton for the match, may be of any length and thickness, as we judge proper; and is to be immersed, and well soaked, in the wetted sulphur, having previously put in the verdigris, and antimony. Sulphur alone will form a blue light.

The matches are afterwards tied to a rod of iron, which is bent according to the design we purpose to form, and to which they are fastened with a very fine iron wire, called the carcase. They are covered with priming paste, and a quick match is tied along the whole length. They are then covered with bands of gray paper, and a piece of port-fire is fixed on the end, to communicate fire.

Sec. XXIX. Of the Purple or Violet Match.

The design is made, and the match is attached, in the same manner as described in the last section; but without bending it. The preparation is as follows: Make a decoction of jujubes, which have been peeled, and stoned, and thicken it by adding as much of the flour of sulphur, as will bring it to a proper consistence. The cotton is then covered with this mixture, in the manner before stated; its thickness to be determined, according to the time required for it to burn. While hot, the match is primed by rolling it in meal powder. It is then suffered to dry. The design, it is to be observed, ought to be supported at the distance of four or five inches from the rods which hold it, by small cross pieces of iron, to prevent it taking fire; a circumstance necessary to be guarded against.

Sec. XXX. Of Meteors.

Artificial fire-works, to resemble meteors in the atmosphere, have, if properly prepared and exhibited, a brilliant appearance. The composition must be projected to a great height, which is either done by rockets, or from mortars. Meteors are made in the same manner as shining marrons, which we have already described, except, however, that they are of a very large size and usually weigh ten pounds. The larger they are made the better, and the more grand is their effect. See Shining Marrons.