On the top of the serpents, in each mortar, lay some paper or tow; then carry a leader from one mortar to the other, and from all the outside mortars to that in the middle. These leaders are to be put between the cases and the sides of the mortar, down to the powder at bottom. In the centre of the middle mortar, fix a fire pump, or brilliant fountain, and sufficiently long to project out of the mouth of the mortar. Then secure the mortars, by pasting paper over their tops.
The nest of serpents (as mortars thus prepared are called) is fired by lighting the fire-pump, which, when consumed, will communicate to all the mortars at once by means of the leaders.
Single mortars are called pots des aigrettes. If the mortars, when loaded, are sent to any distance, or liable to be much moved, the firing powder should be secured from getting amongst the serpents, which would endanger the mortars, as well as injure their performance. To prevent this accident, the mortars are to be loaded in the following manner; First, put in the firing powder, and spread it equally; then cut a round piece of blue touch paper, equal to the exterior diameter of the mortar, and draw a circle on it equal to its interior diameter, and notch it as far as that circle: then paste that part, which is notched, and put it in the mortar close to the powder, and stick the pasted edge to the mortar. This will secure the powder at the bottom, so that it may be moved and carried without receiving any damage.
For mortars of six, eight, or ten inches diameter, the serpents should be made in one and two-ounce cases, six or seven inches long, and fired by a leader, brought out of the mouth of the mortar, and turned down the outside; its end being covered with paper, to prevent the sparks of the other works from setting it on fire. For a six-inch mortar, let the quantity of powder for firing be two ounces; for an eight-inch, two ounces and three-quarters; and for a ten-inch, three ounces and three-quarters. Care must be taken in these, as well as small mortars, not to put the serpents in tight, for fear of bursting the mortars. These mortars may be loaded with stars, crackers, &c.
Sec. VII. Of Making, Loading, and Firing Pots des Brins.
These are formed of pasteboard, and must be rolled pretty thick. They are usually made three or four inches in diameter, and four diameters long; and pinched at one end like common cases. A number of these are placed on a plank in the following manner: Having fixed on a plank two rows of wooden pegs, cut, in the bottom of the plank, a groove the whole length, under each row of pegs. Then through the centre of each peg, bore a hole down to the groove at bottom, and, on every peg, fix and glue a pot, whose mouth must fit tight on the peg. Through all the holes, run a quick-match, one end of which must go into the pot, and the other into the groove, having a match laid in the groove from end to end, and covered with paper; so that, when lighted at one end, it may discharge the whole almost at the same instant. In all the pots, put about one ounce of meal and grained powder. Then in some put stars, and in others rains, snakes, serpents, crackers, &c. When they are all loaded, paste paper over their mouths. Two or three hundred of these pots being fired together, make a brilliant appearance by affording so great a variety of fires.
Sec. VIII. Remarks respecting Fire Pots.
Fire pots, called also pots of ordnance, in pyrotechny, are nothing more than vessels used in, as well as for, the exhibition of artificial fire-works. They are generally formed of thick pasteboard, made by pasting together six or eight sheets of paper, of two inches interior diameter, three inches exterior diameter, and fifteen inches long. They are always placed upon a solid block or plank, and preserved in a firm position. There is a stopper or plug made of wood, which goes one inch into each case or pot, and is there glued and secured by nails. This plug is turned with a screw, which enters the plank, and preserves the pot in a steady position. The plank, on which the pots rest, is usually three inches wide, an inch and a half thick, and sufficiently long to receive twelve pots, placed at the distance of half an inch apart. Before the pots are fixed on, a hole is made through each plug in its centre, to receive a quick match, which passes through to the composition. A groove is also made in the plank, in its length, one-third of an inch square; and in such a manner, that the holes, which communicate to the interior of the pots through the plugs, must come in the middle of the groove. When the quick-match is put through the plugs, to communicate with the interior of the pots, we must leave about two inches on the outside. At each hole, also, we put some priming paste, and then permit it to dry.
If it is required to discharge them all at once, this may be done by making a communication through the groove, by means of leaders in the manner before mentioned; and covering the leaders with four or five bands of paper, and setting the match or leader on fire. If, on the contrary, they are to go off in succession, the groove is filled with bran, which is pressed with the fingers, and is then covered with paper. The match of communication with the pots must, however, be preserved. The bran causes the fire to communicate gradually from one to the other.