"Circumfulgore is a naval machine. It was the invention of the people of Majolica, and it is made of a circle of bombards, of whatever number you please – as long as it is not an uneven number, since, in order for the blow to be effective, and for the craft not to recoil, it is necessary for one bombard to be at the back of and to block another. And to do this, it is necessary to give fire at the same time to two contrary bombards, so that if one causes recoil toward one direction, the other will contradict it."
The model represents a study of a multiple
bombard conceived for positioning on the bridge
of a ship. Leonardo called it "circumtronito" or
"circumfolgore" (rotating thunder
or rotating lightning). It is constituted of a section of the hull of a watercraft, on which an artillery turret is installed, composed of a turning platform on which 12 firearm barrels are arranged. The bombards, probably breech-loading, are arranged radially so as to allow them to shoot simultaneously in opposite directions, thus balancing the recoils after shots so that the ship would not be subject to dangerous yawing or rolling. The presence of several bombards also allowed rapid successions of firing without having to interrupt operations for reloading the firearms.
The model is based on the drawings:
- Manuscript B f. 82 v. (1487-1492)
Paris, Institut de France
- Codex Atlanticus f. 1a r. (1503-1505)
Milano, Biblioteca Ambrosiana