Briefly, the grand idea of M. Paixhans consisted in the establishment of a fleet of steam vessels armed with guns designed to project charged shells horizontally at considerable velocities. But as this consummation could only be attained by degrees, he proposed that in the meantime the existing French fleet should be re-armed in such a way as to give to each ship a maximum of force combined with unity of calibre. This part of his scheme was applicable to solid shot (_boulets massifs_) as well as to shell (_boulets creux_). But the former he considered too ineffectual for use in future sea engagements. Although they might be the most suitable projectiles for the destruction of land works, the breaching of ramparts and the battering of stone walls, yet hollow shot, filled with powder and other combustible material, were far better adapted to rend and set fire to defences of wood, impregnated with tar, and, in time of action, replete with every species of inflammable substance, and crowded with combatants. No, M. Paixhans hoped to make solid shots entirely obsolete, by adopting, in combination with small steam vessels, or, for the present, in combination with the existing fleets of sailing ships, an ordnance specially dedicated to shell fire, and to shell fire alone. By its means the enormous superiority of Great Britain would be effectually eliminated, or transferred into the hands of France; her material would be rendered suddenly obsolete, her maritime power would shrivel; and the power of France would be augmented to such a degree that the defeat of these islands might at last be encompassed. Such was the amiable intention of M. Paixhans.