Who Invented the Mechanical Clock?

In researching the previous post, I came across a reference to Pope Sylvester II (formerly Gerbert d'Aurillac, c.946 - 1003) inventing the mechanical clock. The source of this was the William Godwin's final book, Lives of the Necromancers, An Account of the Most Eminent Persons in Successive Ages Who Have Claimed for Themselves, or to Whom Has Been Imputed by Others, The Exercise of Magical Powers [1834]:

This generous adventurer, prompted by an insatiable thirst for information, is said to have secretly withdrawn himself from his monastery of Fleury in Burgundy, and to have spent several years among the Saracens of Cordova. Here be acquired a knowledge of the language and learning of the Arabians, particularly of their astronomy, geometry and arithmetic; and he is understood to have been the first that imparted to the north and west of Europe a knowledge of the Arabic numerals, a science which at first sight might be despised for its simplicity, but which in its consequences is no inconsiderable instrument in subtilising the powers of human intellect. He likewise introduced the use of clocks. He is also represented to have made an extraordinary proficiency in the art of magic; and among other things...

The italics are mine. A little further along, Godwin adds a footnote that tells us his information comes from William of Malmesbury. William (c.1095 - c.1143) was the foremost English historian of the 12th century. Not exactly a contemporary, but maybe near enough that the memories and stories were still fresh? It would be difficult to determine the accuracy of this report, especially in the context of a brief blog post. Fortunately, I don't have to.

As it turns out, Marek Otisk of the University of Ostrava (Czechoslovakia) published an article on this very topic in September 2020, Gerbert of Aurillac (Pope Sylvester II) as a Clockmaker. He examines the reports from William of Malmesbury, the Chronicle of Thietmar of Merseburg (died c.1018), and a much later record (someone who died in 1610). Among his detailed examination of these and other historical records we learn that although William claims Gerbert built a clock in Reims, a friend of Gerbert's (Richest of Reims), writes about Gerbert's stay in Reims in detail and never mentions a clock. Otisk concludes that William's ascribing of the creation of a clock to Gerbert cannot be trusted.

The later report by the Benedictine monk Arnold Wion, who died about 1610, claims Gerbert built a clepsydra, a water clock, in Ravenna. What we know of Gerber's time in Ravenna, however, is that it was very short; again, no contemporary accounts support this story.

Thietmar of Merseburg tells a different story, that Gerbert created a clock in Magdeburg. Thietmar was a bishop and close friend of Holy Roman Emperor Henry II, who succeeded Otto III, credited with making Gerbert into Pope Sylvester II. Thietmar's Chronicle includes a specific detail about Gerbert creating, in Magdeburg, "created clocks (horologium) which he correctly calibrated according to the Polar star (stella, dux nautarum) which he observed through an observation tube (fistula)." [Otisk, p.32] Otisk likes this account because both Thietmar and Gerbert were in Magdeburg in the late 990s, and very likely crossed paths several times.

The use of the word horologium is misleading, however. We use it for the word "clock," but it is more likely that Gerbert was creating a calibrated armillary, or possible even an astrolabe, which he knew about from his exposure to science being done by Islamic philosophers.

So I can't tell you who created the first mechanical clock. But the question of horologium remains: when long-ago writers refer to "clocks," what exactly did they mean? What constituted a clock? There were several ways to measure time without staring at the sun and judging, and I'll talk about those devices tomorrow.

The Death of William Rufus

Recent posts have talked about the sons of William the Conqueror: how he left the kingdom to his second son, William Rufus; how the eldest, Robert Curthose, had a temper and was shunted off to Normandy; how the youngest, Henry, took the throne upon his older brother's death during a hunting accident. We haven't yet talked about the hunting accident.

from Ridpath's Universal History (1895) 

If it was an accident.

On 2 August, 1100, King William II, called "Rufus" (probably on account of a red face), went hunting with a party of men that included his younger brother, Henry. The Anglo-Saxon Chronicle states that he was "shot by an arrow by one of his own men." A later reference says an arrow glanced off a tree and went through his lung.

Details are scant. This was somewhere in the New Forest; the exact location is unknown, although later legend has picked a spot. In fact, a few centuries later, a stone was erected purporting to be on the site of the oak tree from which the arrow glanced.

William of Malmesbury claims that an archer named Walter Tyrell was responsible for the errant arrow, despite the fact that he was considered an excellent shot. Rather than carry the king's body back for burial, the hunting party left it there. Henry rushed to Winchester to seize control of the treasury and declare himself king; he was confirmed the next day. A peasant later came across the body and caused it to be brought to Winchester for burial.

Some historians claim that, if Henry wanted his brother killed, he would have waited; that William and Robert were headed for inevitable conflict, and that he merely had to wait until one of them eliminated the other, and assassinate the remaining brother. We know, however, that Robert was still away on the First Crusade, the money for which he had been given by William. At that time, it looked like Henry's elder brothers were getting along. Henry might also have been aware of the agreement between his brothers to be each other's heir. If Henry wanted his chance to be king, he had to seize it and consolidate power while Robert was far away and in no position to assert his claim. Henry also used his coronation charter, the Charter of Liberties, to cement the loyalty of the nobles.

We will never know for certain if William's death was an accident, but the situation so clearly benefitted his younger brother that it is difficult to shake the suspicion that it was engineered.

The Name Glastonbury

Glastonbury is a small town in Somerset, England, that has been inhabited since Neolithic times. A recent post discussed the discovery of early medieval glass-making furnaces at the site of the now ruined Glastonbury Abbey. This prompted some to point out to me that Glastonbury "must have been known" for glass production—it is "right there in the name." Let us address that.

Remains of the nave of Glastonbury Abbey

In his book The Flowering Hawthorn, Hugh Ross Williamson tells the story of St. Collen. Collen was a 7th century hermit who took up residence at what is now Glastonbury. Williamson relates how the saint encountered Gwyn, King of the Fairies, in a magical glass castle on Glastonbury Tor. Rejecting the fairies' offer of food and drink, he cast holy water on them, causing all to vanish. Numerous versions of this story exist, but Williamson's 1962 book is the only version that introduces glass as the material involved. As a source for the site's name, this is not reliable.

William of Malmesbury refers to its earliest name as Ynys Witrin, which some translate as "Isle of Glass" based on the fact that English "vitreous" comes from Latin "vitrum" meaning "glass." "Isle of Glass" would more properly be Ynys Gwydr, however. "Witrin" is a puzzle, but no serious scholar thinks it is from Latin for "glass." (The "Isle" makes sense because, in earlier times, higher sea levels turned some hilly areas into islands.) Malmesbury does suggest that the place was named for someone named Glast. Since the first recording of the name is Glestingaburg, the place of Glestinga. No one knows exactly to what Glestinga refers.

But it's not about glass.

1066: The Other New King

Edgar and his sister, St. Margaret, landing at
Wearmouth after their ship was blown off course

Yesterday was the anniversary of the Battle of Hastings, when the forces of William the Conqueror (mentioned many times; see one of them here) defeated the English and killed King Harold Godwinson. The link in the previous sentence for the Battle of Hastings tells more of the story than is generally known, namely that Harold's army had been on the march and fighting for weeks prior to Hastings. Also not generally known is that someone was proclaimed King of England the day after the Battle of Hastings, and it was not William of Normandy.

Edward the Confessor supposedly saw the impending trouble with succession to the throne of England and saw a way out: he had a nephew who was the legitimate heir: Edward (1016-1057), called "the Exile, who had fled to Hungary after being ousted from England after the defeat of his father (Edmund II "Ironside," c.989-1016) by King Cnut. Edward the Confessor had called Edward the Exile back to England to make him his heir. Sadly, the Exile died very soon after his arrival back in England in 1057. History does not record a reason, but it is possible that he was eliminated by the Godwinsons, who were very powerful and wanted to see Harold succeed to the throne.

Edward the Exile had left children behind on the continent, however. Edgar the Ætheling (c.1051-c.1126) was only a teen in 1066, but his youth was no bar to the succession. The witenagemot, the council of wise men that approved the succession in Anglo-Saxon England, met in London and chose Edgar as king the day after Harold fell at Hastings, and sent for him to return to England and lead the opposition to William of Normandy.

The men who chose him, however, chose not to defend their choice and resist William as his forces approached; instead, they negotiated with William for a peaceful turnover of the kingdom. In December, the aristocracy of England met with William at Berkhamstead to submit themselves to his rule and hand over Edgar. William took Edgar and some other English leaders into custody in order to ensure future cooperation.

In 1068, Edgar fled captivity with his mother and two sisters (Margaret and Cristina) to return to Hungary, but their ship was blown off course and landed in the north of England, where they were taken in by Malcolm* III Canmore, king of Scotland. Malcolm married Edward's sister Margaret (who later became Saint Margaret). Edgar had an "on again, off again" relationship with William and an adventure-filled life. He was still alive in 1125 according to William of Malmesbury, so his date of death assumed to be c.1026.

*Malcolm was the model for the character in Shakespeare's MacBeth.

The Flying Monk

Did a monk of the 11th century accomplish the first manned flight? There is reason to believe so.

In the Gesta Regum Anglorum [Deeds of the English Kings] of William of Malmesbury, we read of a monk named Eilmer in Malmesbury Abbey who launched himself from the Abbey's tower with a set of home-made wings. According to the story, he glided more than a furlong (a furlong is 220 yards, or just over 200 meters). Then, suddenly realizing how precarious his position was, he panicked, lost control, and crashed, breaking both legs. He had extreme difficulty walking for the rest of his life.

How likely is this story to be true? Let's first consider what we might call "incidental" evidence. William is not just reporting a legend: although he lived after Eilmer, he was in the same Abbey, and very likely got the story from elders who knew Eilmer and had witnessed the experiment first-hand.

William also records a curious detail: that Eilmer ever after claimed his failure was due to not constructing a tail for his device. This suggests that Eilmer really did study birds in flight, and realized that a tail is also important to steer and brake for landing. Unfortunately for the history of manned flight, the abbot forbade him or anyone from repeating the crippling experience.

But was such a flight possible? Several historians have weighed in, and even the United States Air Force is willing to accept it. The conditions that make it believable are as follows:

The Abbey was situated at a cliff edge over the Avon River that would have created strong updrafts. Eilmer would have seen how jackdaws use the strong updraft to glide and soar without the need to flap. The tower would have been about 80 feet high, giving him additional altitude for catching an updraft. If Eilmer were a small man, calculations suggest that a light and strong frame of willow or ash, covered with parchment or light cloth, would only need an area of 100 square feet to support his weight. William says the wings were attached to Eilmer's hands as well as feet—this supports the notion that they covered a larger area than just wings attached to arms.

Local legend says his landing spot is an area now called "Oliver's Lane." (Ralph Higden's Polychronicon—mentioned here—erroneously referred to Eilmer as Oliver, and the name stuck.) Given the constant wind conditions and the distance he is supposed to have flown, Oliver's Lane is precisely where modern calculations based on wind currents place his likely landing spot. The gliding flight would have lasted about 15 seconds.

He lived a long time afterward, becoming known for scholarship. His writing on astronomy existed and was well-known into the 16th century, but has been lost since. Also lost to history is the tavern "The Flying Monk" in Malmesbury, which has since been replaced by a shopping center.

The White Ship

William of Malmesbury tells us of a disastrous event on 25 November 1120: the sinking of the White Ship off the coast of Normandy:

Here also perished with William, Richard, another of the King's sons, whom a woman without rank had borne him, before his accession, a brave youth, and dear to his father from his obedience; Richard d'Avranches, second Earl of Chester, and his brother Otheur; Geoffrey Ridel; Walter of Everci; Geoffrey, archdeacon of Hereford; the Countess of Chester; the king's niece Lucia-Mahaut of Blois; and many others ... No ship ever brought so much misery to England. [Gesta Regum Anglorum]

The William mentioned was the only surviving heir of King Henry I of England.

The White Ship was a magnificent vessel that had recently been refurbished with new materials. Its captain was the son of one of William of Normandy's pilots; in fact, the father had piloted William's flagship in the flotilla that conquered England. Had the captain had his way, all might have been well. Here's what happened:

King Henry and his sons were in Normandy, and returning to England. The ship was offered to him for the voyage, but as he had already made arrangements and was ready to depart, he gave the honor of the White Ship to his sons. Henry left for England. The sons, on their own and in command of a fancy ship, were generous in allowing the crew and passengers to start drinking while dockside. Later, with night approaching and alcohol flowing, they decided (foolishly) to set off and beat the king to England; they were sure the ship could do it, despite being weighed down by about 300 bodies. So they set off into the darkness, with a tipsy crew.

The ship hit a rock, tearing a hole in the side. William of Malmesbury's version has one survivor, clinging to the rock all night; Orderic Vitalis says there were two. In either case, we have some details that might be true, such as Prince William escaping in a boat, but going back to rescue his half-sister and having his boat capsized when too many people tried to climb aboard.

Prince William's death forced Henry to name his daughter Matilda his heir. When Henry himself died in 1135, his nephew, Stephen of Blois, decided a firm male ruler for England was more important than honoring the oaths he made to support Matilda. Stephen crossed the Channel to claim the throne, and set off almost two decades of civil war.

William of Malmesbury

In the 12th century in England, the practice of writing histories was becoming relatively common. The Anglo-Saxon Chronicles and the Chronicle of Melrose were ongoing, and Orderic Vitalis and the prolific Eadmer were writing their histories. Since I cast doubt on William of Malmesbury (1095-c.1143) in yesterday's post, however, I thought he deserved some attention.

William of Malmesbury's aim was not simply to write a history, but to produce a great literary work that was worthy of the greatest historian England had yet known. His Preface begins:

The history of the English, from their arrival in Britain to his own times, has been written by Bede, a man of singular learning and modesty, in a clear and captivating style. After him you will not, in my opinion, easily find any person who has attempted to compose in Latin the history of this people. Let others declare whether their researches in this respect have been, or are likely to be, more fortunate; my own labor, though diligent in the extreme, has, down to this period, been without its reward.

Bede (673-735) was universally respected, so much so that it was rare to see his name without the modifier "Venerable" before it. After praising Bede's singular position in English literature, William attempts to produce a work that equals or surpasses it. The result was the Gesta Regum Anglorum (Deeds of the Kings of the English).

And according to many scholars, he succeeded. In the opinion of Milton, William was "both for style and judgment by far the best writer of all." He included anecdotes and detailed descriptions of important figures—far more historically valuable information than the often terse Anglo-Saxon Chronicles. Like Bede, and unlike other historians, he showed the cause and the effect of historical events and the actions of kings. His account of the First Crusade is detailed and colorful.

He followed this work with Gesta Pontificum (Deeds of Pontiffs), a history of abbeys and monasteries in England. About the year 1140, he revised both works, updating them, and began an addendum to the first, his Historia novella (History of new[er] things). His patron in all this was Robert, Earl of Gloucester. As a son of King Henry, Robert was fairly powerful; it is thought that Robert would have made William the abbot of Malmesbury Abbey, but William preferred to concentrate on his learning instead of administrative duties.

That learning certainly contributed to his writing. It is believed that some of his information, such as what he has to say about Wulfstan, the Bishop of Worcester, comes from the account by Wulfstan's contemporary, Coleman. But that is how medieval scholars managed: they took from available works, and providing attribution was not as important as making your own work as complete as possible. William's works remain the best accounts we have of life in England in the first few generations after the Norman Conquest.

Æthelstan—The Forgotten King

In the history of the Middle Ages, there must be many "forgotten kings"—those whose rules were too short or too obscure or too trivial to add any momentous events to the modern consciousness (many people know the phrase "The Norman Conquest" even if they couldn't tell you details). In the case of Æthelstan (c.894-939), however, his reign was significant enough for the history of England that it is a shame that he is not known better.

Perhaps there is irony that part of his undeserved obscurity is actually paired with elements that should have helped to make him more noteworthy. To a modern world who wants only a few highlights from studying the past, his accomplishments are overshadowed in classrooms by those of his grandfather, Alfred, the only king in English history to have earned the epithet "the Great."

Also, we have an account about him from William of Malmesbury (c.1095-1143) who said of Æthelstan "no one more just or more learned ever governed the kingdom." Most modern scholars, however, mistrust the Malmesbury account (although some have argued that internal evidence suggests that Malmesbury is actually drawing on an earlier and probably reliable biography). A 10th century Latin poem says of him: "Holy King Æthelstan, whose esteem flourishes and whose honor endures everywhere."

The Anglo-Saxon Chronicle often only mentions military engagements, and therefore neglects his administrative and economic achievements. But in his lifetime, he was praised as "the English Charlemagne." He financed Catholic churches. He regulated currency and controlled the weight of silver coins and passed laws to penalize currency fraud. (In the image below of the Æthelstan penny, note the "braiding" around the edge that prevents "coin clippers" from shaving off silver in order to spend a coin of less weight.) He regulated commerce, confining it to the burh (Anglo-Saxon "town"; think Modern English "burg"), encouraging the growth of towns. He consolidated the wilderness areas and settlements in the Midlands, creating new shires, asserting royal control and law more consistently over the entire country.

Æthelstan silver penny

He also made valuable alliances. He married off his half-sisters to European noble families, so that he had connections with brothers-in-law such as the future Holy Roman Emperor Otto. King Harald Fair-Hair of Norway sent his son Haakon to foster at Æthelstan's court. When Harald died and Haakon's brother Eirik Bloodaxe proclaimed himself king, Æthelstan equipped Haakon with ships and men to take his rightful place as King of Norway (which he did).

He won a decisive battle, the Battle of Brunanburh in 937; summed up by Winston Churchill:

The whole of North Britain—Celtic, Danish and Norwegian, pagan and Christian—together presented a hostile front under Constantine, king of the Scots, and Olaf of Dublin, with Viking reinforcements from Norway. [History of the English-Speaking People]

After Æthelstan's victory, he could rightfully call himself "the King of all the English"—the first ruler on that island to be able to do so.

Upon his death in 939, he was laid to rest in Malmesbury Abbey—a place for which he had great affection—rather than the traditional Winchester, which was the seat of power for the royal family of Wessex.

Perhaps, as one fan of Æthelstan put it, his fame is tenuous because there are too many things about his life that cannot be grasped succinctly and with certainty: did he possess the greatest collection of sacred relics at the time, including the Spear of Longinus? Why did he not marry and have children? Did he have a half-brother killed? Was his mother a concubine? These questions, however, should not prevent knowing something about a remarkable and forward-looking figure from England's past.