Ballista, Catapult, Trebuchet...

...Onager, Mangonel, Springald, Polybolos—all words for devices that propelled heavy objects toward an enemy; not to mention Cheiroballista, Manuballista, Carroballista, and Couillard.

[source]

Ever since early man learned that hitting someone in the head with a rock was an efficient way to win an argument, he probably started thinking "Hmmm. If only I could hit him without getting too close."

The invention of the catapult [Latin "catapulta" from Greek "kata"=down and "pallo"=to hurl] is credited to the ancient Greeks—as this blog has mentioned previously—although a similar device is described even earlier in the Old Testament:

And he made in Jerusalem engines, invented by cunning men, to be on the towers and upon the bulwarks, to shoot arrows and great stones withal. And his name spread far abroad; for he was marvellously helped, till he was strong. [King James Bible, 2 Chronicles 26:15]

Not all catapults are alike. The various names for such devices distinguish different types of them. For instance, the onager [Greek: "wild ass"] was so named because when fired it "bucked and kicked" like a donkey. The trebuchet used a counterweight to provide the thrusting power, rather than the tension of pulling the arm back, as in the standard catapult. The couillard was a French modification on the trebuchet; it used a two-part counterweight, each half swinging to the side of the central arm. The most famous trebuchet was probably one called Warwolf, used by Edward I in 1304 to bring down a section of the walls of Stirling Castle.

The manuballista [Latin: "hand thrower"] was exactly what it sounds like: a hand-operated throwing device, such as used by young boys through the ages and pictured above. The cheiroballista [Greek: "hand thrower'] is considered to be the same device, even though descriptions are not included in the references. The carroballista? A catapult mounted on a carro, a cart, for easy transport.

The springald was essentially a crossbow: smaller, and therefore less tension and less damage, used best against individuals in closer quarters. It first appears in a Byzantine manuscript of the 11th century.

Most of these devices threw a single mass in order to cause great damage to a defensive wall. Occasionally, however, you might want smaller damage but over a wider area. That is when you used the polybolos [Greek: "many thrower"]. Equivalent to a gatling gun rather than a shotgun, the polybolos could fire repeatedly: Philo of Byzantium (c.280-c.220 BCE) describes the mechanism that could fire bolt after bolt—eleven per minute!—once you loaded it up.

If you wish to build your own device, consider this store.

A Sultan's Observatory

The Ulugh Beg Observatory Museum, built in 1970

Ulugh Beg is the more familiar name of Mīrzā Muhammad Tāraghay bin Shāhrukh (22 March 1394 - 27 October 1449). "Ulugh Beg" is more of a nickname, meaning "Great Ruler."

He was a grandson of Tamerlane who became sultan in Samarkand while still a teenager. He decided to turn Samarkand into an intellectual center, building a university and inviting scholars to take up residence.

He also built the Ulugh Beg Observatory in 1420, where some of the finest Islamic astronomers worked and studied, but only those whom Ulugh personally approved. The picture here is a modern structure on the site of the original, which was destroyed by religious fanatics in 1449. An excavation uncovered its primary feature—a giant sextant:

The so-called "sextant" obviously would have extended well above the ground (as the drawing shows) and likely was closer to being a quadrant. As Krisciunas points out in his interesting discussion of the instrument, it "was by far the largest meridian instrument ever built." Fragments of the curved measuring track have survived with markings for around 20 degrees; this is about the highest point that observations likely would have been made. The "sextant" would have been used to measure the angle of elevation of major heavenly bodies, especially at the time of the winter and summer solstices. Light

from the given body, passing through a controlled opening, would have shone on the curved track, which is marked very precisely with degrees and minutes. "It could achieve a resolution of several seconds of arc--on the order of a six-hundredth of a degree, or the diameter of an American penny at a distance of more than half a kilometer" (Krisciunas). It is not clear whether more than the sun and moon could have been measured in this fashion, since planets, for example, would not have cast sufficient light. [link]

Building a giant permanent astronomical instrument was a unique idea at the time—remember that this was 200 years prior to the invention of a telescope. He created a catalog of over 1018 stars, discovering and correcting many inaccuracies in the star tables created by Ptolemy. Copies of these star charts are on display at the Ulugh Beg Observatory Museum; the originals are in the Bodleian Library in Oxford.

Knitting, Part 1

Naalbinding technique [link]

Technically, today's post is not about knitting, but about an earlier technique with a similar result known as naalbinding. Naalbinding, or nålebinding, is Danish for "needle-binding." In English it is sometimes referred to as "knotless knitting."

Some archeological finds have been designated as early knitting when they were really naalbinding. Knitting as we know it today appears near the end of the first millennium CE, whereas threads woven by naalbinding can be found dating to centuries earlier.

The difference is that, while knitting involves a continuous row of loops linked together by the use of two needles, naalbinding uses a needle to pass the whole length of the thread/yarn through each loop, and the loops must be bound together during the creation process (see the illustration above). In knitting, simply turning the piece around once all the links have been transferred to one needle means that the next row will be automatically linked to the row on the needle. Naalbinding uses shorter pieces of yarn, not one long continuous piece.

Despite the Danish label, naalbinding's earliest examples are found around the world, in socks used by Coptic Christians of the 4th century and hats and shawls of the inhabitants of what is now Peru dating to 300 BCE. The pair of wool socks shown here, meant to be worn with sandals, is in the Victoria & Albert Museum in London. They were excavated in Egypt and date to between 300 and 500 CE.

For those wishing to know more, a how-to for the process is explained and illustrated here.

The Larder

In the Book of Proverbs, we find "Like a snow-cooled drink at harvest time is a trustworthy messenger to the one who sends him; he refreshes the spirit of his master." [25:13, New International Version] It is believed that the tribes, like the Greeks and Romans, used snow to cool drinks.

Packed in straw and buried deep, snow from the mountains could be preserved for a time. References in the Classical Era to cooled drinks are not matched, however, by references to cooled foods. The scale required to refrigerate food was too large, even if they had thought of it. (Actually, the Persians did think of it, digging pits filled with ice and placing food there. This method did not seem to spread elsewhere.)

The Middle Ages found different ways to work with food over time. The Middle English word larder denoted a place to store meat (and is related to the word "lard"). It would of course be in the coolest part of the house, on the side facing away from the sun and in the lowest part of the house. It also should be close to where the food was going to be prepared and cooked. (An underground root cellar was for long-term storage, different from a larder.) The larder in a large household might be run by a larderer, responsible for maintaining the meat and fish used by the kitchen.

The room might also contain a thrawl, a stone slab on which meat would be laid to keep it cooler than it would be on another surface. (This word was used in Yorkshire and Derbyshire, England.)

There were other ways to preserve food, rather than cold. Brining, hanging to dry, smoking, curing into sausage and bacon, etc. The notion that the spice trade was so important to medieval Europe because they had to cover the taste of rotten meat is silly. Preserving meat for use later does not require it to be fresh-looking and plastic-wrapped as our modern society prefers.

The Abbasid Caliphate

The Abbasid Caliphate has only been mentioned so far as a target of the Assassins, but deserves more attention. Descended from Muhammad's uncle Abbas, the caliphate took power from the Umayyad caliphate and ruled from 750 until its conquest by Mongols in 1258.

That means that the Abbasid Caliphate was "in charge" during many of the Islamic interaction with Europe mentioned in this blog:

• Abu Ma'shar, the Father of Arab Astrology, who brought commentaries on Aristotle to Western Europeans
• The astronomer Abd al-Rahman al-Sufi, who reconciled Greek and Arab star charts
• Averroes the Commentator
• Avicenna the surgeon
• ...and, of course, it was during this time that Algebra came to be

Besides math and philosophy, the Abbasid Caliphate was at the forefront of technology, adopting the use of Chinese paper-making techniques and gunpowder. Arabs developed the sextant, windmills for industrial use, and kerosene from petroleum.

The Abbasid's first capital was Kufa, on the banks of the Euphrates, but they shortly chose a different city, whose only shortcoming was that it did not exist.

On 30 July, 762, that would change; but that's a story for tomorrow.

A New Plough

A diagram of the heavy plough with mouldboard

One of the tools that most shaped European culture and improved life in the Middle Ages was a new type of plough. Ploughs drawn by animals to break up the earth were used as far back as 2500 BCE in the Indus Valley; however, those ploughs were simple wooden devices, mostly some form of stick or rake that would scratch the surface of the earth so that seed could be broadcast and covered with dirt. This worked well in the light sandy soils of the Mediterranean and Egypt, but the heavy, wet, clay-laden soils of Europe were another mater. Simple scratch ploughs could not make a dent in those heavy soils, laid down by glacial advance.

Someone devised a plough with two particular features: the coulter and the mouldboard. The coulter (#4 in the diagram) is a vertical cutting blade that cuts a furrow. That isn't enough, however. The mouldboard (#7) is a curved blade that turns a layer of earth over, exposing it and creating a deeper furrow than a scratch plough. Improvements in the smelting and shaping iron by 900 CE made the coulter, the chisel (#5), and the main share (#6) efficient so that the mouldboard could do its job properly.

When dragged through a field the coulter cuts down into the soil and the share cuts horizontally from the previous furrow to the vertical cut. This releases a rectangular strip of sod that is then lifted by the share and carried by the mouldboard up and over, so that the strip of sod (slice of the topsoil) that is being cut lifts and rolls over as the plough moves forward, dropping back to the ground upside down into the furrow and onto the turned soil from the previous run down the field. [link]

A side-effect of this type of plough is that deep furrows are created that help drainage. If excessive water from spring rains can be diverted from fields rather than standing in pools, planting can take place earlier; a longer growing season results, less susceptible to water damage of seedlings.

Around the same time, Europe started experimenting with crop rotation. The practice of using a field every other year for a different purpose was already in place, but three-field crop rotation in which one field is left fallow began to create healthier crops and higher yields at harvest time.

I will not go as far as James Burke* does and say that everything comes from the plough—predictability of future crops, pottery because you need to store grain, writing because you need to make a potter's mark, weaving because you are growing flax, et cetera—but the development of the mouldboard plough literally made a dent in man's difficulties in growing food in European soil. It contributed to population growth and to other advances in technology and civilization.

*The inspiration for this post comes from memories of James Burke's groundbreaking Connections.

Assembly Line

Detail of the Venetian Arsenal from theCivitates Orbis Terrarum [1572]

When we think of Venice and boats, we think of gondolas being poled through quiet canals. Venice, however, was a powerful presence in the Mediterranean not because of gondolas but because of larger ships that transported people—either for military or religious purposes.*

At some point—possibly in the very early 1100s during the reign of Doge Ordelafo Faliero, or perhaps even earlier—a complex of state-owned shipyards was begun, called the Arsenale di Venezia ["Venetian Arsenal"]. It was designed to provide private shipbuilders with a facility to produce ships for themselves or the state. In 1320, the complex was upgraded to the Nuovo Arsenale ["New Arsenal"] as a place to "build and maintain navy and merchant ships, all in one location." [source]

The Arsenal is probably the first example of large-scale factory work prior to the Industrial Revolution. The complex grew to cover 110 acres, and had a forest dedicated to its lumber needs. The workers, called arsenalotti, numbered in the thousands at the height of production and were said to be able to produce a ship in less than 24 hours. One of their techniques was to build the frame first rather than the hull first. Once the frame was finished, different crews could move in with their pre-fabricated parts for assembly. Rigging, sails, weapons, etc., were prepared by separate teams for the appropriate type of vessel. Dante even mentions this process in Canto xxi of Inferno. These specialists also made improvements in technology, particularly in weaponry. Gunpowder weapons—bombards and handguns—were a particular interest.

Much of the complex is now in ruins, but you can see the Porta Magna, the "Great Gate" that provided the seaward entrance, here.

*Some day I promise to get to my favorite Crusade, the 4th, and how it went horribly wrong.

Button, Button

Bronze-Iron Age buttons as ornament. [source]

Although evidence of buttons exists as far back as the classical era, it appears that they were used as ornamentation on clothing rather than a way to fasten clothing,

the earliest known being found at Mohenjo-daro in the Indus Valley [now Pakistan]. It is made of a curved shell and about 5000 years old. [Ian McNeil, An Encyclopedia of the History of Technology]

Rows of buttons as a necessary part of clothing were unknown. Usually a single button—a flat decorated surface with a loop attached to the back—was put on clothing to pin up a single fold of fabric.

The first evidence of "functional buttons"—used to attach clothing so that it fit snugly about the body—is found in art. Statuary on the Adamspforte ("Adam's gate") at Bamberg Cathedral (carved c.1235) in Germany shows a button holding clothing together.

By the late 1300s, buttons were being applied to all sorts of clothing in order to make it fit more closely to the body. One of the modifications that made buttons work well was the addition of reinforced button holes to clothing, which spread in the later 1200s.

A late medieval button from England [source]

Besides a change in fashion, was the addition of buttons and buttonholes significant? Well, one theory (shared by James Burke of Connections fame and Lynn White, author of several essays and books on the history of technology) is that the spread of better-fitting clothing made people warmer in cold weather and therefore increased their health...or, at least, decreased susceptibility to any illnesses that were exacerbated by cold temperatures.

This seems odd to the modern age, because we take form-fitting clothing for granted. Didn't they have looms and weaving? Of course. But much form-fitting fabric in the Middle Ages didn't appear until the development of knitting.

But that's a story for another day.