A Lecture, Or Essay On the most efficacious means of Preserving The Lives Of Shipwrecked Sailors And The Shipwreck

17 ing, lift up what was the bottom part, and draw out the pegs, leaving the rope ready laid on what before was the lid, but which then serves as a platform. SECTION OF THE FRAME. i À il The greatest care must be taken to keep the mortar dry, not to load it till everything is ready, and it is then to be instantly fired. As it would be impossible to prime it with loose powder in a storm, a tube may be constructed of common writing-paper, the outer edge being cemented with a little gum, in this form, being- filled with finely-powdered or mealed gunpowder, made into a paste with spirits of wine ; and when in a drying state, if a needle is thrust through the centre, and the hole it makes left open, when in- flamed, a stream of fire (from the atmospheric air) will rush with great force down the aperture, and explode gunpowder at a considerable distance. Great difficulties having been experienced to keep a match lighted to fire the mortar, (on which all depends,) a pistol was fitted up with a tin box over the lock, to protect it from the wind and rain, the flame of which, at the discharge, is so dilated, by the barrel being cut transversely at the muzzle, as to require but little exactness in the direction of the aim. Two occurrences of this sort induced me to inquire whether, by a chemical process, instant and certain ignition might not be produced, to prevent similar accidents : one was occa- sioned by my pistol getting wet, from the sea washing over it, and c