Engines of Our Ingenuity

No. 2220:
MAITRE JEHAN de MONTESILER

by John H. Lienhard

Today, Joan of Arc's sniper. The University of Houston's College of Engineering presents this series about the machines that make our civilization run, and the people whose ingenuity created them.

An article in my new Mechanical Engineering magazine, about the history of gun barrels, begins with the story of Jehan de Montesiler at the Siege of Orléans. Before we meet Jehan, some background: The Siege of Orléans was where French forces, led by Joan of Arc, defeated the English in 1429. Two years later, after she was captured by the English, she was burned at the stake. Twenty-five years after her death, the Pope, having called for a rehabilitation trial, declared Joan to be innocent and a martyr.

During Joan's posthumous trial, testimony was given by a government official, Jean d'Aulon, who'd once served as her squire. He mentioned that he'd assigned Jehan as a sniper to take out an important English officer during the siege.

And here the fun begins. d'Aulon and other witnesses tell how Jehan taunted the English with his gun -- how he killed five men with two shots, how he picked people off from outside arrow range, how he devastated the English with his marksmanship.

We need only glance at the history of firearms to wonder how that could be. By then, a gun was still just a metal tube, typically brass -- maybe iron -- with a hook in front. It rested on a tall stick, set in the ground. The muzzle was placed in a notch in a parapet or in a large shield. The hook was set outside, to keep the gun from recoiling into the gunner. The gun's bore might've been an inch and a quarter -- an inch and a half -- and the projectile, a metal or stone ball.

Early hand cannon

Jehan's gun at Orléans could've been no more sophisticated than that. By the way, matchlock guns didn't appear until forty years after Orléans. Jehan had to light a fuse at the back of the tube to fire it. He couldn't possibly have sighted down the barrel. The only way he could've hit anything, would've been to place his gun, then take practice shots to zero in on his target.

So, as we ponder this story, we seem to hang somewhere between Edison and Dedalus. Historians have, with patience, been able to reconstruct, very reliably, what Edison did and did not accomplish. Not many secrets there. But did ancient Dedalus actually build some sort of flying contraption that propelled him into the corridors of myth? That, we'll probably never know.

But Jehan's gun comes to rest in history's cracks. Much of the story could be true. An excellent Internet account points out that Jehan existed in isolation. Joan's army was not equipped with an artillery unit. He's presented as a lone ranger -- an isolated, clever athlete who took a new technology to its limits in ways that others could not. But, while Joan of Arc was rehabilitated by the Pope, historians wield less power. Jehan de Montesiler must continue to tease us with his marginal plausibility.

I'm John Lienhard, at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)


R. O. Woods, Straight and True. Mechanical Engineering, Vol. 129, No. 5, May 2007, 38-41.

For more Maitre Jehan de Montesiler, see: http://xenophongroup.com/montjoie/jean-m.htm

B. S. Hall, Weapons and Warfare in Renaissance Europe: Gunpowder, Technology, and Tactics. (Baltimore: The Johns Hopkins Univ. Press, 1997).

Images courtesy of Wikepedia Commons.


Hand cannon from 1400
Image of a hand cannon by Conrad Kyeser, ca. 1405.


The Engines of Our Ingenuity is Copyright © 1988-2006 by John H. Lienhard.