Known Details

Using the reports of contemporary eyewitnesses, but also the things that Bessler himself describes in his publications, there are various technical details and hints of a more general nature that can be joined together into a patchy puzzle. When he moved to Cassel in 1716, he wrote a book consisting of two parts written in verse.

Downloadable as a PDF file or available as a CD-ROM at the Digitization Center of the University of Göttingen (GDZ) on:
https://gdz.sub.uni-goettingen.de/id/PPN616141514?tify–%7B%22%20%5B%5B5%5D%2C12view%22%A %22info%22%7D

Alternatively, Google: https://books.google.de/books/about/Orffyreus-apological-Po%C3%ABsie-unde-poetis.html?id-YmVdqJBHlrwC&redir escÃ y

Part 1: “Orffyrei Apological Poetry”. (An autobiographical description of his life and his invention. Poetry because Bessler made wrote it in rhymes.)

Part 2: “That which was recklessly, dishonorably, and falsely torn down, slandered, yet only in vain supposedly discovered*) by Christian Wagner in Leipzig, but now saved, defended, just and truly remaining, still undiscovered Orffyrean PERPETUUM MOBILE. Hastily drafted in German verses at the urgent request of many great patrons by the inventor of the Perpetuum Mobile, Orffyreus himself"

*) “discovered” here more likely meaning “uncovered” and referring to the secret drive of his wheel. Wagner, together with Gärtner and Borlach, on the 22nd July 1715, violently invaded Bessler's house and inspected the mechanism of the “perpetuum mobile” against the will of the inventor, in order to figure out its function. However, the action came to nothing, since Bessler had taken operationally important parts out as a precaution. (See Biography.)

The “Apological Poetry” is briefly referred to on this website as “Apologia” (defence speech). The following lines were taken from it and adapted to today's German written language as necessary (and then translated to English).

The dog also crawls out of the hut,
But only as far as the chain goes.
The beautiful treasures and machines
He knows how to serve in a very friendly manner.
He well wags his tail,
Crawls on his stomach through the hoop,
But soon the skinny whackers will come to him
And whack him on his paws.
You see a wheel and no wheel either,
Because it has rims and yet is doesn't.
Runs without internal and external wheels,
Cymbal weight, wind nor clock spring.
Here you see half of it, there you see it completely;
It flaunts like a peacock's tail.
It runs to the right and to the left;
you can only wave your fingers at it.
It spreads lengthwise and crosswise;
Here it is full, there it is empty;
One thing consists of the three kingdoms;
You have tangible signs.
Without sulfur, salt, Mercury*)
Something has to go away soon too.

*) Merkurius, after the roman messender of the gods, Mercurius (Mercury), alchemical term for mercury, which is still used in homeopathy today. The scientific-chemical name for mercury is Hydrar Gyrum, (Latin for liquid silver). Chemical sign: “Hg”.

The last four lines are interesting. By invoking “sulphur, salt, mercury,” Bessler gives an indication that his “perpetuum mobile” was not magic, but consisted only of earthly things. As a doctor, he knew the teachings of Paracelsus, who had lived about 200 years before him. He had adopted a system of alchemy that had long been known from the Arab world and which, in his opinion, could be used to assess things that existed in the world. In other words, material substances, but also the nature of diseases and their healing. He called it the system of three principles (Tria Principia), also referred to by Bessler as the “three kingdoms”. For Paracelsus, the liquid, mobile mercury symbolized the spirit, which combines with the burning sulfur and the solid salt to form the substances of the earth. He put it like this:

”All visible manifestations of this world came into being through the three principles: “The visible and tangible is the body of the world, which consists of the three primordial substances, sulphur, mercury and salt. From these three things come all properties, modality and being, nature and the like. They show every doctor that he should perceive the effects of these three things with his seeing eyes, then he will understand the invisible.”

It is no longer quite clear why Bessler chose the verse form. Prose would certainly be better received by readers today. Also because his poetic talent can only be described as mediocre. His rhymes are often uneven, but that doesn't detract from him as a person, because the historical interest lies in this man's invention.

Bessler, who had initially experimented unsuccessfully for ten years and already believed in a curse that was preventing him from success, finally achieved a breakthrough. This gave him a sense of triumph that he trumpeted at every opportunity. His competitors, who had been denied success, felt humiliated by this. Some of them became his bitterest opponents. Among them Christian Wagner from Leipzig and Andreas Gärtner as well as Johann Gottfried Borlach from Dresden. The idea that these gentlemen would rack their brains over his ambiguities must have given Bessler a certain satisfaction when he was composing his verses. They fought him and repeatedly appealed to the public to discredit him as a fraud. The fact that he was not happy about this but felt a desire for revenge can be seen on almost every page of his Apologia. It is full of scorn and ridicule. It's hard to count how often the names of his opponents appear in it. He obviously wanted to provoke them and at the same vent his wrath on them. This seems rather repulsive to today's reader, because Bessler would have shown true magnamity if he had simply ignored his opponents.

Though, silence, silence and enough,
Enough, otherwise the enemy will just become wise.
The enemy who wants to drool on me,
Drool, I should be excited,
Excited and red-handed
Throw the coat off the wheel.
But this wish will fail him,
His snapping won't get me there.

Bessler's books probably had a very simple purpose besides challenging his opponents. He wanted to glean admiration from his readers. A completely legitimate and humanly understandable concern. On the other hand, publishing the books was what is now called marketing. His invention was to be made known beyond the borders of Germany. The aim was to create a desire among the relevant group of people to own this mysterious machine. This follows from the subtitle of his book “The Triumphant Perpetuum Mobile Orffyreanum”. As a PDF download or alternatively as a CD-ROM from:
https://gdz.sub.uni-goettingen.de/id/PPN513405828

It read: “To all potentates / high leaders, regents and people of standing of the world. Presented in due submission for possible consideration and drafted as a proposal by its inventor Orffyreo”.

The following is known:

There were two different wheels that Bessler developed one after the other. The first one only turned in one direction and is therefore referred to on this website as a unidirectional wheel. It is the one, which was first demonstrated on June 6th, 1712 in Gera on the “Nicolausberg”. Bessler built one in Draschwitz based on exactly the same principle, but with a diameter four times larger. Among those who visited it was the famous mathematician Gottfried Leibniz. Not much of this wheel is known. It was more powerful and faster than the later one that could move in both directions. The Gera wheel had a diameter of 75 cm and a thickness of 10 cm. The wheel made in Draschwitz had a diameter of 10 feet (3 meters) and a thickness of 6 inches (15 cm). Its rotation speed was given as 50 - 55 rpm. The unidirectional wheel had to be permanently braked to bring it to a standstill. If the brake was released, it started on its own. This fact is important because its relevance is easily underestimated when viewed superficially. A wheel that has to be permanently braked to come to a standstill is constantly out of balance. (Something that seasoned physicists consider ludicrous.)

People who want to reinvent this wheel can therefore abandon all ideas that accept temporary states of equilibrium and hope to bridge them with the momentum of the turning wheel. According to Bessler's Apologia, this wheel ran almost silently. There was no rumble of falling masses, but rather a “gentle” impact. According to the description of the Draschwitz wheel in his Apologia, Bessler had dampened potential noise sources with felt. The unidirectional wheel was only half as thick as its bidirectional successor.

The later bidirectional wheel was initially born out of necessity and was demonstrated publicly for the first time in Merseburg. Bessler wanted to counteract the persistent rumors that the movement was caused by a wound up spring. This wheel rotated randomly in both directions, but did not start moving on its own, and had to be started manually. Two fingers were enough for this. When it was given moderate momentum in this way, it immediately began to rotate powerfully as soon as the first weight had “dropped” inside. Each time there was a loud rumbling noise. If you moved the wheel just slightly, it would stop again. In contrast to the unidirectional variant, there were several states of equilibrium that were bridged by inertia during rotation. It could be brought to a standstill by braking.

This was probably the reason why it turned slower than the unidirectional wheel. Several witnesses spoke of 25-26 revolutions per minute for the unloaded bidirectional wheel. (In the report from Bailiff Weisse it says “40 and more”. The latter was probably an observation or transmission error.) Under load it still reached 20 rpm.

Since 8 impact noises were heard during one complete revolution, it was concluded that there were as many individual weights inside that “fell” cyclically. In this context, one can assume that the time intervals between these noises were equal. Otherwise the witnesses would definitely have reported this as a curiosity.

Some of the weights Bessler showed at a demonstration weighed around 4 pounds (about 2 kg). Their shape was cylindrical. It is not known whether all weights had this shape. It also remains unclear whether all the bodies weighed 4 pounds and whether Bessler only used 8 of them. Since they are said to have worked in pairs, there could have been 16, half of which were not acoustically apparent. It is not known how many weights Bessler took out of the wheel when he changed location.

During rotation, the impact noises were heard on the side to which the wheel was currently rotating.

The bidirectional wheel contained at least one steel spring that was temporarily compressed or relaxed when one of the weights was inserted. The witness Wolff, who was near the wheel when Bessler was covertly handling it, heard the characteristic sound of a spring vibrating briefly. He concluded that when Bessler attached one of the weights, he pushed down this spring. It is obvious that this would have been the case with each of the weights and that there must therefore have been several springs in the wheel. This fact is significant because it conveys that the wheel would not have been able to run without springs. Even if Wolff only saw the bidirectional wheel in action, there is a high probability that the unidirectional wheel was also equipped with springs. This results from Bessler's statement that the gravitational drive of a wheel is only possible with a single operating principle. In the article "Speculation", the author states that the bidirectional wheel probably consisted of two unidirectional drives arranged one above the other, which could be set in motion by choice (in opposite directions). The double thickness of the wheel and its comparatively short development point in this direction.

The wheel's performance is said to have been proportional to its size. When tested in Merseburg, the diameter was 6 Leipzig cubits (3.40 m) and the thickness was 1 shoe (30 cm). The box of bricks, lifted by a rope from this wheel, weighed an estimated 70 pounds. This corresponds to around 35 kg and just over 1 kg per 10 cm of wheel diameter. Certainly not breathtaking, but still remarkable when you consider that a single drive weight only weighed around 2 kg. Part of the power was also needed to overcome operational friction. The Bessler wheel rotated in simple plain bearings. The winding process of the rope on the axle (turn to turn) as well as the rotation of two deflection pulleys caused further friction losses. (One on the roof and one on the floor.) There were also losses due to the rope's churning.

Since the Merseburg wheel reached exactly 20 revolutions per minute under load, it took exactly 3 seconds for one complete revolution. This makes calculating its performance easy.

The axle diameter was given by ‘sGravesande as 6 inches (15.24 cm). This corresponds to a circumference of 15.24 cm x 3.14159 (Pi) = 47.86 cm. Since the rope was wrapped around this axis, the box was raised by 47.86 cm / 3 = 15.95 cm (approx. 16 cm) per second. This results in a performance of

35 kp x 0.16 m/sec = 0.075 PS = 55.16 Watt

Bessler had arranged the examination himself. Therefore, one can assume that with the 70 pounds he reached the performance limit of the wheel. If more had been possible, he would have used it to impress the audience even more. Since both the axle diameter and the 70 pounds were eyewitness estimates, the performance calculated above can of course only be an approximation. For the sake of simplicity, one can assume about 60 watts for the bidirectional Merseburg wheel, although this not only includes the friction losses, but also takes into account that the rope was probably wound up in several layers. This would have increased the circumference.

Incidentally, the Merseburg test showed that the wheel could not only lift loads, but also lower them in a controlled manner without becoming significantly faster.

The mechanism was apparently simple. Landgrave Karl said that any apprentice carpenter could build such a wheel. This finding referred to the bidirectional wheel.

The main material used by Bessler was wood, the bearings were made of iron. The mechanical parts were apparently crude and therefore not susceptible to mechanical complications or wear and tear. The wheel easily survived a 54-day endurance test.