Sixteen pounds of refined lakepetre are put into a copper vessel, to which four quarts of water are added. It is placed over a charcoal fire to boil; as the water evaporates it is well stirred with copper-shod spatulas or paddles, occasionally taking it off the fire, until the evaporation ceases; and when brought to a fine powder it is sifted through a hair sieve, and spread on paper to cool.
To extract saltpetre from damaged gunpowder.
Dissolve the powder in warm water, filter the solution through fine linen bags, and then evaporate the water by boiling it, until the solution is of sufficient strength to crystallize.
SERPENTS, OR SQUIBS.
The case is made by rolling stout cartridge paper in slips of 6 or 8 inches in breadth three times round a former, and pasting down the last fold. The case, having been choked at one end, is filled about two-thirds with the composition, and a small piece of paper is inserted, over which powder is placed, and this end is secured with twine. At the other extremity, moist powder with touch-paper is inserted. To introduce the composition into the case, a quill, cut into the form of a spoon, may be employed, and the composition must be rammed down by a few strokes of a mallet on an iron rod tipped with brass.
| Composition. | |||
| 1. | lb. oz. | 2. | lb. oz. |
| Mealed powder | 1 8 | 1 0 | |
| Charcoal | 4 | 1 | |
| Sulphur | 1 | 0 | |
| Saltpetre | 3 | 1¾ | |
SHELLS, OR AERIAL GLOBES.
These globes are made of wood, and their thickness is equal to about a twelfth part of their diameters. The usual charge is an ounce of powder for a shell of 4 lb. weight, and 2 ounces for a shell of 8 lb. They may be fired from any mortars that have not a chamber.
To form the shell.