Thursday, January 11, 2007

A Composite Deed of Arms in the Early 15th Century.

This is generally based on The Ordinance and Form of Fighting Within Lists (before 1397) in the Hastings MS. “The king” has been replaced with the more general “the judge” and sections that seem to pertain purely to judicial duels have been omitted. Some of the proclamations are taken from the Scales-Bastard contest of 1467 in Excerpta historica. Additional details from other contemporary accounts are given in italics.

The judge shall find the field to fight in. And the lists shall be made and devised by the constable. And it is to be considered that the lists shall be sixty paces of length and forty paces of breadth in good manner, and firm, stable, and hard, and evenly made without great stones, and that the earth shall be flat. And that the lists be strongly barred round about and a gate in the east and another in the west with good and strong barriers of seven foot of height or more. And it is to wit that there should be false lists without the principal lists between which the men of the constable and the marshal and sergeants of arms should be for to keep and defend if any would make any offense or affray against the cries made.... .and these men should be armed at all points.

The day of the battle the judge shall be in a siege or in a scaffold and a place shall be made for the constable and marshal at the stair foot of the said scaffold where they shall be.

(There may also be scaffolds for “the nobles of the country, the ladies and damsels, as well as the principal citizens of both sexes.” Pious champions may choose to hear mass and take communion prior to the combat. Less pious ones may simply drink and eat very well, if Jean Juvenal des Ursins’ report of the English team of 1402 is correct.)

The appellant shall come to the east gate of the lists in such manner as he will fight, with his arms and weapons assigned to him… , and there he shall abide till he be led in by the constable and the marshal. And the constable shall ask him what man he is which is come armed to the gate of the lists and what name he has and for what cause he is come. The appellant shall answer: "I am such a man -- A. de K. -- the appellant, which is come this journey to accomplish and perform the acts comprised in articles sent unto (name of the defendant)"
(If other appellants come with him they are announced as well)

Then shall he open the gates of the lists and make him enter with his said arms, points, victuals and lawful necessaries upon him and also his council with him; he shall lead him before the judge (where he may do his reverence) and then to his tent, where he shall abide till the defendant be come.

(He may have a chair and be accompanied by minstrels and trumpets. His friends and councilors may show their support by leading his horse or carrying his weapons. If each side is a team rather than one man, they may either share a tent or each have their own pavilion. The mid 15th c. How a Man Shall be Armed text, also in the Hastings MS, has a more complete list of “lawfull necessaries”)

A tente muste be pight in the felde
Also a cheyre
Also a basyn
Also vj loves of breed
Also ij galones of wyne
Also a messe of mete flesshe or fisshe
Also a borde and a peyre of trestelis to sette his mete and drynke on
Also a borde clothe
Also a knyf for to cutte his mete
Also a cuppe to drynke of
Also a glas with a drynke made
Also a dosen tresses of armynge poyntis
Also an hamyr and pynsones and a bicorne
Also a smale nayles a dosen
Also a spere a longe swerde shorte swerde and dagger
Also a kerchif to hele the viser of his bascinet
Also a pensell to bere in his hande of his avowyre

(Earlier described as “his pensill in his hande peyntid of seynt George or oure lady to blesse him with as he gooth towarde the felde and in the felde”. The religious pennoncel or other banner probably began as a peculiar feature of the judicial duel but by the 1440s champions at the Pas d’Armes de l’Arbre de Charlemagne are described as making a grand cross with their bannerole before taking up their weapons. )

In the same manner shall be done for the defendant, but that he shall enter in at the west gate of the lists....

And when brought before the judge he may say:

"Right high, right mighty and right excellent prince, I am come hither before your presence as my judge in this party, to accomplish and fulfill the acts of arms contained in certain chapters to me sent by (name of appellant), under the seal of his arms, that here is."

And the judge then gives him leave and license to perform them.

(There is some variation in custom, and in some places the defendant enters the lists first. The weapons may be examined and measured, and sometimes equal weapons are supplied by the champion issuing the challenge, or a common length for the weapons is specified in the challenge)

And then the constable shall command the marshal for to cry at the four corners of the lists in manner as follows: "Oyez, Oyez, Oyez. We charge and command by the judge's constable and marshal that none of great value and of little estate, of what condition or nation that he be, be so hardy henceforward to come nigh the lists by four feet or to speak or to cry or to make countenance or token or semblance or noise whereby neither of these two parties A. de K., appellor, and C. de B., defender, may take advantage the one upon the other, upon peril of losing life and limb and their goods at the judge's will."


Since it is so that the most christian and victorious prince

by the grace of God King of England and of France and Lord of Ireland, hath licensed and admitted the right noble and worshipful lords and knights,
(or list other rank if applicable)


(Appellant and Defendant’s Names and Titles)

to furnish certain deeds of arms such as be comprised in certain articles delivered unto his highness by the said

(Appellant’s Name)
sealed by the said

(Defendant’s Name)
with the seal of his arms, for the augmentation of martial discipline and knightly honor, necessary for the tuition of the faith catholic against heretics and miscreants, and to the defense of the right of kings and princes and their estates publics:— for so much we charge and command you, on the behalf of our most dread Sovereign Lord (add here present, if sovereign is present in person) and on my Lords the Constable and Marshall, that no manner of man of what estate degree or condition he be of, approach the lists, save such as be assigned, nor make any noise murmur or shout, or any other manner token or sign whereby the said right noble and worshipful lords and knights which this day shall do their arms within these lists, or either of them, shall move, be troubled or comforted; upon pain of imprisonment and fine and ransom at the King’s will.

And afterward the constable and the marshal shall void all manner of people out of the lists except their lieutenants and two knights for the constable and marshal which shall be armed upon their bodies, but they shall have neither knife nor sword upon them nor any other weapon whereby the appellant or the defendant may have advantage because of negligence in keeping them. But the two lieutenants shall have in their hands either one a spear without iron to separate them if the judge will make them leave off in their fighting, whether it be to rest them or other thing whatsoever pleases him.

(These guards and sentinels of the fight within the lists are also called ecoutes or scouts, and there might be as many as ten for a single combat. For a group combat of four against four, there were forty at Valencia in 1403)

The constable sitting in his place before the judge as his vicar general, and the parties made ready to fight as is said by the commandment of the judge, the constable shall say with loud voice as follows: "Lessiez les aler"; (that is to say, "Let them go”) and rest a while; "Lessiez les aler," and rest another while; "Lessiez les aler et fair leur devoir de par dieu"; (that it is to say, "Let them go and do their duty in God's name.") And this said each man shall depart from both parties, so that they may encounter and do that which seems best to them.

Three main sorts of combat may occur in a non-judicial contest, of ascending severity and risk.

1) Single combat for an agreed number of blow: For example, 12 with axe, 12 with sword and 12 with dagger. Each sequence ends when one or the other has struck the agreed number of blows. Between each sequence the champions may separate and each
return to their tent. When the blows are completed the fight is over.

2) Single combat to the utterance. The champions start out fully equipped with axe, sword and dagger, and often a lance for throwing as well. Unless the judge or judges stop the fight, they continue until one surrenders or is killed.

3) Group combat to the utterance: as above, but with teams of equal numbers on each side. In either single or group combat to the utterance, a man that yielded would expect to pay a ransom to be released by his captor.

And if it happen that the judge would take the quarrel in his hands (by throwing down his baton) and make them agree without more fighting, then the constable, taking the one party, and the marshal, the other, shall lead them before the judge, and he showing them his will, the said constable and marshal shall lead them to the one part of the lists with all their points and armor as they are found and having when the judge took the quarrel in his hands as is said. And so they shall be led out of the gate of the lists evenly, so that the one go not before the other by no way in any thing; for since he hath taken the quarrel in his hands, it should be dishonest that either of the parties should have more dishonor than the other. Wherefore it has been said by many ancient men that he that goeth first out of the lists hath the disworship...

Dillon, "On a MS Collection of Ordinances of Chivalry of the Fifteenth Century, Belonging to Lord Hastings," Archaeologia, LVII (1902), 62-66.
Excerpta historica: or, Illustrations of English history [edited by Samuel Bentley] London, 1831 pp. 204208

Saturday, January 06, 2007

Converting Peter Van Dorns bowling-ball data to Joules of Energy

Sean Powell was kind enough to send me an explanation of how to convert the data from a test of bowling balls struck with rattan swords into joules of energy. As he points out in an earlier comment, unfortunately we don't have enought data to calculate from this how much kinetic energy was in the sword before it hit.

His explantion follows. While he provided tables for all the different post heights in the test, I was unable to align the data in a readable form in blogger, so I've reduced the data to the values for the highest and lowest post.

Converting Peter Van Dorns bowling-ball data to Joules of Energy

Peter has provided us with 3 pieces of data: Weight of a ball, distance the ball drops and how far the ball travels before it lands. This is a classic high school physics problem.

Step 1: Acceleration due to gravity, at the surface of the earth, will be a uniform 32ft/sec^2. (neglecting wind resistance, centripetal force from spin of the earth and the local gravitational effect of the balls mass) For the ball to fall a distance of H it will take a time T regardless of ball weight. H and T are related in the formula:

h = ½ * g * t^2

We can reorder this equation to get

t= (2 * h / g)^.5

(remember to convert h to feet first)
A spread sheet makes the following math easy:
h (in) 46- 58
t (s) 0.49-0.55

Step 2: We know how far a ball travels and how long it takes to get there. That means we can calculate ball velocity with the simple formula:

V = d / t

If we select one particular row to analyze: 12lbs, force Medium we get:

d (in) 38-42
t (s) 0.49-0.55
v (ft/sec) 6.47-6.37

Step 3: We can now calculate Joules of kinetic energy in the ball just after impact with the formula:

KE = ½ * m * v^2

We can also calculate ball momentum just after impact with the formula:

Momentum = m * v

But of course to keep doing this in Imperial units is a pain since we need to convert weight in pounds to mass in slugs and then re-convert slug-ft^2/sec^2 into Joules so first we will convert weight and distance to metric.

v (ft/sec) 6.47-6.37
v (m/sec) 1.97-1.94
Weight (lbs) 12
Mass (kg) 5.44
KE (kg-m^2/s^2)(J) 10.58-10.25
Mo (kg-m/s) 10.73-10.57

No both of these values seem rather consistent BUT for every different ball mass there is a different distance. If we look at the 8lb ball and the 16lb ball we will eventually get:

KE (J)=(kg*m^2/s^2) Medium
8lb 15.32-15.38
12lb 10.58-10.25
16lb 7.66-7.94

M (kg*m/s) Medium
8lb 10.55-10.57
12lb 10.73-10.57
16lb 10.55-10.73

And we can clearly see that kinetic energy of the lighter balls is higher then the heavier balls but the momentum of the various balls is NOT dependent upon weight.

Tuesday, January 02, 2007

How hard can human muscles strike with a sword?

One interesting data point is a survey carried out within the Society for Creative Anachronism.

If you're familiar with armored combat within the Society, skip this paragraph. The Society, or SCA uses weapons made of rattan and other materials that approximate the weight and balance of medieval weapons. The goal in armored combat is to strike a "good blow", one assumed to hit hard enough to be effective against medieval armor of a particular period. Lighter blows than this standard are ignored.

This article describes a survey carried out some years back to attempt an objective quantification of this subjective standard by smacking a bowling ball off a post and measuring how far it flew before hitting the ground. It should be possible to calculate the number of Joules transmitted to the target. Unfortunately, the calculations are trickier than I originally thought, and for now I will simply direct you to the first comment below, which responded to an earlier draft. These estimates seem to assume a single handed sword, and a significant number of people can hit harder than the upper end of the range if they want to: the Society frowns upon hitting harder than necessary for safety reasons.

It's also important to remember that many blows in combat land with less than the optimal amount of force the striker could deliver, typically because the target moves in a way that makes the biomechanics less than ideal.