Siege mining: scoppietti poles, a deceiving tunnel, and bastions
Poles of firing tubes to clear a mine exit, a twisting mine to fool the besieged, and bastion defence
A page on underground siege warfare. Leonardo describes poles packed with scoppietti (small firing tubes) to be thrust up out of a mine exit to sweep away the men gathered around it, and a mine deliberately dug on a twisting course so that it appears to emerge at one point but breaks through on the opposite side of the fortress. Further notes and sketches treat a bastion, a mobile shield full of scoppietti for the attackers, and the poles of various lengths used to defend a bastion. The large central drawing is captioned as a mechanism for producing the beat of the wings; additional untranscribed writing sits inside the boxed diagram at lower left.
On this page
Poles packed with firing tubes to sweep a mine exit
Poles full of scoppietti are set against the enemy at the mouth of an underground mine, firing from below upward. Their purpose is to clear the ground of the men standing around the exit. A companion sketch places such poles at a mine that breaks into a well-guarded cellar inside a fortress.
A twisting mine to deceive the besieged (m, a, b)
Since the besieged watch for hidden tunnels, the miner should make a show of digging toward one place while, circling the fortress, he breaks out on the opposite side. The scheme is lettered m b a, with b near the exit into a cellar a. A great reserve of men waits to burst through once the dividing wall is broken.
Defending a bastion with poles of varied length
A note gives a way of defending a bastion, and with which poles, that is with how many different lengths. A separate small drawing is simply labelled as a bastion. The cross-section at lower right shows the profile of such a work.
A mobile shield of scoppietti for the attackers
When the mine is almost finished and close to a cellar, the sapper breaks through and pushes ahead of himself a screen full of scoppietti. If defenders are found it is fired; if not, it is left unlit so as to make no noise.
The larger figure: a wing-beat mechanism
The prominent central apparatus is captioned as a mechanism for obtaining the beat of the wings. No accompanying prose is transcribed for it, so its workings are read only from the drawing. It stands unusually among the military sketches of this sheet.