Structure

—A rocket is e entially composed of a strong case of paper or wrought iron, inclosing a composition of nitre, charcoal, and sulphur,—the same as gunpowder, except that the ingredients are proportioned for a slower rate of combustion. If penetration and range be required, its head is surmounted by a solid shot; if explosion and incendiary effect, by a shell or spherical case-shot, to which is attached a fuze, which is set on fire when it is reached by the flame of the burning composition. The base is perforated by one or more vents for the escape of the gas generated within, and sometimes with a screw-hole to which a guide-stick is fastened.