Port Fires.
4. Port Fires.—This term is applied to paper tubes, filled with mealed powder, or a similar composition, and which is generally used in setting fire to rockets, or compound fire-works, which require to be lighted very expeditiously; there are two kinds, the one used as above, the other for illuminations: those of the former kind are usually called common Port-Fires, and may be made of any length, but are seldom more than 21 inches; they are rolled on rods about half an inch in diameter, and made of cartridge paper in three or four folds till their exterior diameter is about five-eighths of an inch, the last fold being well secured at the edge by paste, and one end pinched or folded down. The moulds, five-eighths of an inch diameter, should be made of brass or tin, and to take to pieces length-wise, forming two semi-cylindrical tubes, and when used, to be connected together by several rings fitted to the outside of the tube. If about an inch of metal be made fast to one extremity of the half tube of the diameter of the rod or former, it will supersede the necessity of a foot, and be much more convenient; but the part of the former as we may term it, must be made very fast to the tube, or it will easily be detached by the ramming of the cases. The composition for filling these cases generally consists of salt-petre, sulphur, and mealed powder, in various proportions, according to the intended strength of the fire, though salt-petre is generally in the greatest proportions. When the fire is to be very slow, saw-dust is sometimes added, and the ingredients are frequently moistened with spirits of wine or linseed oil; these compositions should not be rammed too hard. In using this kind of Port Fires, the close end is fixed in a metal socket made like a port crayon, which is attached to a stick of sufficient length to reach any required part of the fire-work.