Fire lances have for a long period been commonly used as torches for purposes of general illumination during a display of fireworks at night in the open air. But, though they produce a handsome effect, objection to their employment in this way arises from the fact that their powerful light diminishes the brilliance of the spectacle offered by the various pieces set off. Moreover, the amount of smoke given off is likely to prove troublesome. For these reasons, it is better that the lances, if thus used, should be reduced to a very small size, from which may be formed figures of any desired outline without causing inconvenience, while, by reason of their limited light and short duration, they afford an agreeable contrast to the other exhibitions, and this contrast is emphasized by the whiteness of their fire. (PL V, fig.9.)
Customarily, the lances have an interior diameter of from 4 to 5 lines, with about 15 inches of length, when they are designed to serve for purposes of illumination. The small lances used in forming designs have a diameter of 3 lines, with a length of from 3 to 4 inches.
The cases are made of paper, which is very thin so that it may burn at the same time as the composition. Four turns of paper suffice for the large size, and either two or three turns for the small size. The manner of molding these has already been described.
Four sticks of various lengths are used for loading the large lances. The first has the same length as the case, and each of the others is shorter by one-fourth than that which preceded it. The case is loaded entirely by hand without the assistance of either mold or base. Ten blows from a light mallet are used for each charge. The lance is not choked after it has been loaded. The opening of the case is merely closed by wet prime set about the match end.
In order to form a figure by means of small lances, holes are pierced following the contour of the desired design in a board on which this has been traced. These holes are disposed at distances of 1 1/2 or 2 inches from one another. The lances are placed in the holes, and fastened there with glue.
Another method is to drive small nails into the wood, following the design as with the holes, and then to set the lances over them.
Port fires are placed above the lances after they are arranged for the design. The port fires are opened with scissors at the point of contact with each lance in such a manner that the match inclosed within them touches on the priming of the lances. The hole is then covered over with paper for the twin purposes of holding the port fire in its position on the lance and of protecting the communication.