We will have occasion hereafter, to notice the different modes of fixing, and arranging stars; the formation of strung stars, rolled and drove stars, &c. Great care must be taken in making stars, that the several ingredients are reduced to a fine powder, and the composition is well worked and mixed. The instructions for rolling of stars, are the following: Before we begin to roll, take a pound of the composition, and wet it with the following liquid, sufficient to make it stick together, and roll easy, viz: Spirit of wine one quart, in which dissolve 1/4 of an ounce of isinglass. If a great quantity of composition be wetted at once, the spirit will evaporate, and leave it dry, before all the stars are rolled. Having rolled one portion, shake the stars in meal-powder, and set them to dry, which will require three or four days; but, if wanted for immediate use, they may be dried in an earthen pan, over a slow heat, or in an oven. It is very difficult to make the stars all of an equal size, when the composition is taken up promiscuously with the fingers; but, by the following method, they may be made very exact: When the mixture is moistened properly, roll it on a flat smooth stone, and cut it into square pieces, making each square large enough for the stars required. There is another method used by some, which consists in rolling the composition in long pieces, and then cutting off the stars; so that each star will be of a cylindrical form. This method, however, is not so good as the former; for, in order to make the composition roll in this manner, it must be made very wet, which makes the stars heavy, as well as weakens their effect. All stars must be kept as much from the air as possible; otherwise they will lose their properties.
What are called, in pyrotechny, the flaming stars, with brilliant wheels, the moon and seven stars, the transparent stars with illuminated rays, the transparent table star, the projected star, and the illuminated star wheel, are all particular exhibitions, which are produced by disposing the works in a certain form and order. They have, therefore, no relation to those preparations, or compositions, which produce stars. They will be considered, however, in their respective places, when we treat of the disposition and arrangement of fire-works.
As a general theory of stars, we may remark, that while combustion ensues, as in other fire-works, in the manner explained in our chapter on that subject, some substances are always employed, which have, for their object, two effects in particular; viz. that of modifying the appearance of the flame, by producing certain colours, and increasing or diminishing the degree of combustion, and that of throwing out, at the same time, scintillations or sparks. The latter effect, however, is not so great in stars, as in some other preparations, which are designed especially for the purpose. That certain substances have a particular effect, which uniformly ensues, under the same circumstances, is a fact obvious to all. Hence, we see in all the numerous formulæ for stars, for those that produce a red, a blue, a yellow, or any other flame, and those which form tails, sparks, &c. being modified according to circumstances, that the effect is owing to the presence of one, and sometimes to the action of two, three, and more substances, co-operating together. That combustion may be greater or less; that it may be accelerated, retarded, and otherwise modified; that the flame of inflammable bodies may be varied, as to colour, by the presence of foreign substances; that the action of one substance upon another, in certain elevated temperatures, may produce results which would not take place at a reduced temperature; that, for the support of combustion, the oxygen of the nitre, or the oxygen gas of the atmosphere, may, singly, or jointly, produce that effect, as in instances of rapid combustion, and in the combustion of bodies actually thrown out in the state of ignition;—these are so many considerations, all necessary to be attended to, in establishing a theory of stars, as well as of fire-works in general.
Sec. XI. Of the Fire-rain, (filamentous.)
Fire-rains are generally two inches long, and formed on a small copper, iron, or wooden roller, two and a half lines in diameter. Two turns of the paper are considered sufficient for them. They are twisted at their extremities, and struck afterwards on a table, to flatten and close them in the same manner as common cases. Using a small funnel, they are charged with the following composition, in the same manner as serpents. Grained powder, however, is not employed. When charged, they are primed with paste, having also, a piece of cotton-match attached to them.
Composition.
| Meal-powder, | 16 | oz. |
| Fine oak charcoal, | 3 | — |
Six ounces of charcoal to a pound of powder, is the formula of Bigot. The one given is that of Morel.
Sec. XII. Of Sparks.
The second kind of rain-fire, called sparks, is made in the following manner: The composition is formed into a thick liquid paste with brandy; and eight ounces of flax are immersed in it, and kept there for some time. The flax is then rolled into small balls, about the size of peas. They are then rolled in dry meal-powder, and hung up in the open air, in the shade to dry.