The rope leading out of the window and the wooden box hanging on it are part of the woodcut visible on our start page. For this purpose, a rope pulley was attached to a rafter in the Green Court in Merseburg. According to the witnesses, the other end of the rope was wrapped directly around the axis of the wheel. The angle of the rope is not reproduced correctly due to the fact that the wheel of the start page is part of a larger woodcut, on which it is displayed a second time in side view (see the red colouring in the diagram). After redirection via a roll attached to the ground, the rope wraps around the axis of this side view.

The side view shown on the left part also contains the stamp mill, which is described under the name “pounding pillars” in the following report by Gottfried Teuber. The woodcut is therefore not a pictorial documentation of the wheel that was tested in Merseburg. The same applies to the pendulums, which are not mentioned in a single witness report. It may have been a Bessler gimmick, or they were added in artistic liberty. Later it was occasionally claimed that the pendulums had served to balance the wheel or guarantee a smooth run. However, neither makes much sense. A disturbing imbalance could have been eliminated much easier with additional, permanently arranged masses. Since a lower speed was recorded under load, the pendulum would have hindered the process as a separate vibratory system. This is addressed In the article “Speculation”. 

Today, the “Green Court” no longer exists. It was completely demolished in the 70s of the 20th century as part of the city renewal. In its place is the Herder-Gymnasium depicted above. For admirers of Bessler, it is, however, a memorable place. After all, due to the test in 1715, his invention went down in history as the “Merseburg wheel”. 

Merseburg is a charming city. If you visit Halle an der Saale as a tourist, you should definitely have enough time to pay a visit to the cathedral town of Merseburg, which is just a short distance away to the south. Merseburg is the city of magical spells. The history of the cathedral also includes the raven tale, which goes back to Bishop Thilo von Trotha. 

The “Green Court”, mentioned in the report of Bailiff Weiße, was the place where the inspection was carried out. It was a complex of buildings located near the Sixti Church at Leunaer Straße 6. It was built in the 17th century and was a large plot with a residential building, outbuildings, barns, stables etc. Above is a drawing from the “Merseburger Kreiskalender” from 1940. It was kindly made available by the Historical Municipal Archive Merseburg. It says there:
“In front of the Sixti gate, opposite the city cemetery, there has been a “Green Court” since the old days. This property is already mentioned in medieval times. A citizen of our city, Johannes Andreas, sold it to the Sixti-Foundation in 1350 together with the adjacent “Great Court”. Of course, there were not yet the different buildings we see today. They are even missing from the views of the city of Merseburg, drawn by Dilich around 1630 and by Merian, around 1650. We only hear more about the “Green Court” in the second half of the 17th century. During this time, Günther von Grießheim built the house (and probably also the outbuildings). In the old fountain, the year 1668 is carved into a stone. The construction was probably built at that time. The Grießheims were a respected noble family in Merseburg during the time of the duchy.” 

Here is a photo of the nearby Sixti Church. It was built in the 11th century, destroyed in the Thirty Years' War, and never rebuilt afterwards. In Bessler's time it was already a ruin. The tower has been used as a water reservoir since 1889. 

Johann Christian Wolff (1679-1754), Professor of Mathematics and Philosophy in Halle

Wolff wrote in a letter to Leibniz: “When Orffyreus exhibited his extraordinary machine to counter the vicious rumors of deception, I made a point of being present. Reality showed that his wheel is far from any deception. The investigation was carried out in the presence of the Duke's commissioners and other guests. When the machine was ready to be set in motion, all the adjacent rooms were opened and the cover of the bearings was completely removed. In order to prevent anyone from seeing the mechanism of his wheel by accident, Bessler covered it. While he did so, he made no secret of the fact that the machine was driven by weights. He had some of these weights wrapped in a cloth, and had us take them into our hands to guess their weight. Each weighed about 4 pounds and clearly had a cylindrical shape. 

I draw from it, but also from other circumstances, the conclusion that the weights were connected with movable or elastic arms at the outer edge of the wheel. While the wheel was spinning, it was clearly possible to hear the weights banging against wooden walls. Through a slot I could see these walls. They were slightly curved. When he took the wheel to another place and reinserted the weights, he pushed down an iron spring, which gave a loud noise on its subsequent return to the top.” 

Professor Christian Wolff was a member of the Royal Society from 1710 on, and had the same standing at the “Berliner Akademie der Wissenschaften” from 1711 onward. In other words, an intellectual heavyweight. 
 

Moritz Wilhelm Duke of Saxe-Merseburg (1688 -1731)

After the early death of his father Christian II, he became the third Duke of Saxe-Merseburg at the age of 6 and ruled until 1731. Because of his love for music, he was later given the nickname “Violin-Duke”. His duchy included the offices of Merseburg, Delitzsch, Lauchstädt, Lützen and Schkeuditz. The area reached directly to the then city limits of Leipzig. Due to the later expansion of Leipzig, the former border town of Lindenau is now one of its districts.

Moritz Wilhelm is occasionally confused with the Duke of Saxe-Zeitz of the same name. The latter, however, came from another family and was 24 years older. He has already been reported on above.

Moritz Wilhelm was an educated man and was considered a kind sovereign. He was impressed by Bessler's invention. Because of the unsilenced charges of fraud, he arranged for a public audit in Merseburg on 31. October 1715. A commission was convened, consisting of respected personalities and famous experts. In addition to the above-mentioned Christian Wolff, the following five people mentioned were the best-known among the commissioners:
Friederich Hoffmann (1660 - 1742), medical professor and founder of the University of Halle
He developed the concept that the human body is a mechanical system that is in constant motion. Possibly an inspiration from the intensive preoccupation with Bessler's invention.
Johann Burkhard Mencke (1674 - 1732), professor of history at the University of Leipzig,
Christoph Semler (1669 - 1740), founder of the first German secondary school,
Christoph Buchta, advisor at the court of the Duke and friend of Leibniz,
Johann Adam Caff,  master builder of Saxony-Weissenfels and Engineer

The report quoted in the biography from Zedler's historical universal dictionary on the “public test” of Merseburg contains the names of all the commission members. (See there.)  

Willem Jacob 'sGravesande (1688-1742), Dutch mathematician

 'sGravesande was a professor at Leiden/Netherlands and a member of the Royal Society of London, of which Isaac Newton was the president. The first experimental detection of the expansion of heated metals is due to 'sGravesande. A London Interest Group (previously the Royal Society itself) commissioned him to make a visit to Bessler to inspect the wheel and to prepare for possible purchase negotiations. It is assumed that Newton was the actual initiator, but wanted to stay in the background. Newton himself, among other things, dealt with the laws of gravity and was certainly very interested in the workings of Bessler's wheel. A letter has been preserved, which 'sGravesande wrote to Isaac Newton on 7.8.1721:

” I thought, Sir, that you would not be displeased to have a rather detailed account of what can be seen from an external examination of a machine concerning which sentiments are so divided, and which is opposed by almost all the accomplished mathematicians. A majority maintain the impossibility of perpetual motion, whence comes the scant attention that has been paid to the machine of Orffyreus.

I know I am inferior to those who have given demonstrations of the impossibility of this motion, nevertheless to explain to you the sentiments with which I examined this machine, I have the honour to tell you that about seven years ago I believe I discovered the paralogism of these demonstrations, in that they could not be applicable to all possible machines; and since then I have always been convinced that one could demonstrate that perpetual motion was not contradictory; and it seemed to me that Mr. Leibnitz was wrong to regard as an axiom the impossibility of perpetual motion; which was nevertheless at the basis of part of his philosophy. Notwithstanding this conviction, I was very far from believing that Orffyreus was accomplished enough to discover perpetual motion. I considered that perpetual motion would not be discovered until after many other inventions, if ever. But since I have examined the machine, I don't know how to express my astonishment.

The inventor has a genius for mechanics, but is not in the least a profound mathematician, however that machine has something surprising about it, even if it be fraudulent. The following is about the machine itself, the interior of which the inventor will not permit to be seen, lest anyone should steal his secret from him.

It is a drum about 14 inches thick by 12 feet diameter; it is very light, being made of several wooden boards assembled with other pieces of wood, in such a way that the interior could be seen from all sides if not for an oilcloth which covers all of the drum. This drum is traversed by an axle of about six inches diameter, terminated at its ends by three-quarter inch iron journals, on which the machine turns. I examined these journals, and I am convinced that nothing from outside contributes to the movement of the machine.

I turned the drum very slowly, and it stood still as soon as I took my hand away; I made it make a turn or two in that way. Then I made it move slightly more quickly; again I made it make a turn or two; but then I was obliged to hold it back continually; for having let it go, it reached in less than two turns its maximum velocity, so that it made twenty-five or twenty-six turns per minute. It kept up this motion some time ago for two months in a sealed room, in which it was impossible that there could have been any fraud."

Landgrave Karl of Hesse-Cassel (1654-1730)

Landgrave Karl was both an absolute ruler and enlightened sovereign. Under his reign, he introduced compulsory education and gave a large number of Huguenots a new home. As a patron of Johann Bessler, to whom he granted refuge at Weissenstein Castle in 1716, he was the only one who the inventor ever confided his secret to. Karl had immediately understood the principle upon looking closely and expressed his wonder that no one else had thought of this amazingly simple principle beforehand. Without ever revealing the secret entrusted to him, he is supposed to later have said that the interior of the wheel had only been a simple arrangement of levers and weights. 

From an authentic point of view, Karl is the most important witness, because he had the certainty that the wheel actually worked as it had always been propagated by his inventor. His desire to see the mechanism was probably less an expression of curiosity or sensationalism, it was probably the need to get a view of Bessler's trustworthiness. He would never have supported him for so many years if there had been any doubt.