In my biography of Johann Bessler, ‘Perpetual Motion; An Ancient Mystery Solved?’, I gave a fairly detailed explanation of how I estimated the weight of the Kassel wheel. I did that a few years ago and I think that I overestimated the weight.
So my new starting point was the translocation of the wheel between the two sets of bearings. Bessler explained that he had to remove the weights prior to translocation because despite the strength of his brother, it ‘would have needed the devil to lift it’. I had previously assumed that the two men might have been able to lift the wheel plus it’s axle and covering oil cloth, if it weighed no more than 300 pounds without the weights, but I now think that would still have been too heavy and prefer to assume an unladen weight of 200 pounds, so they would need to lift 100 pounds each.
How the lift was carried out is not described other than to say the wheel was carried a few steps to the second set of bearings. I speculated the presence of a movable platform on either side of the wheel, stretching from before one set of bearings to beyond the other, raising the two brothers so their shoulders could get under the axle which was at least six feet off the ground. But they could also have done without the platform by using a pair of special ‘Y’ shaped yokes resting on their shoulders and high enough to fit under the axle.
Alternatively if they used two long poles over thirteen foot in length, they could each support opposite ends of the two poles which passed along the two sides of the wheel and under the axle, and simply carry it from A to B. But those poles would be heavy so would add to the weight they had to carry. A system based on two specially adapted wheel barrows designed to fit under the axle would have worked, but I still favour the use of platforms because they would also make it easy for the examiners to study the bearings from close to, and from above, as well as below, something they were easily able to do.
So at what weight did it require ‘the devil to lift it?’ We don’t know how many weights there were, but Christian Wolff describes how he was able to handle one of several weights and estimated its weight at four pounds. If we begin by assuming that there were eight weights, one for each of the eight spokes that’s an extra thirty two pounds to the two hundred pounds of the unladen wheel.
If the wheel contained a mirror image of duplicate weights designed to turn it in either direction then the total weight of the wheel to be lifted is 264 pounds, but is that beyond the capabilities of the two brothers to lift it? I don’t think it’s enough, and of course many people think the mirrored mechanism wasn’t necessary leaving the total at 232.
Perhaps there were two four pound weights on each spoke? That would make the total either 264 or 328 pounds if it used the mirror image. I’m not even sure if Bessler would think that was too heavy, but at this point it’s worth considering how long it would take to remove and replace 32, 4 pound weights every time he did a translocation. How patient would his audience of high ranking men be? I don’t know, but Bessler was a natural showman I imagine he explained in humorous tones what he was doing and why, but it was still a fairly lengthy task.
Wolff describes the sound of a spring being ‘raised aloft’, but I don’t know what that would sound like, but I think it must have related to the way the weights were attached to levers. The simplest method allowing quick attachment and detachment would be some kind of split pin above and below the weights through the lever even so it might take at least 30 minutes to detach and reattach the weights, and move the wheel, each time he did a translocation.
Of course as many here know, I still think there might have been only five mechanisms which would reduce the weight of the wheel, leaving the option to add more weights.
Finally why did Bessler wrap the weights in a handkerchief prior to allowing them to be handled by witnesses? Although Wolff thought it was done to disguise the appearance of the weights I think it was to protect his visitors hands from animal grease used as a lubricant in the mechanisms. This brings me to another potentially limiting factor - the bearings,
I think the Kassel wheel was designed to achieve the endurance test, so it was designed to turn more slowly, yet still have the ability to lift the 70 pound box of stones. It also had to have bearings which could survive the endurance test without failing too soon. They were only three quarters of an inch thick to reduce friction and must have been well greased. Animal fats or combinations of olive oil or linseed oil and thickeners such as chalk were commonly used but were probably messy and with Bessler handling weights frequently they needed to be wrapped to protect his visitors from spoiling their hands and clothing. Apparently some lubricants in common use were ‘black slugs’ so that would increase the desire not to offend his audience by spreading their residue!
The size of the bearings must have limited the weight they could support without failing and therefore I would limit the maximum weight of the whole wheel to be no more than 500 pounds, which allows for more weights if necessary. These extra weights might be necessary in order to achieve the lifting of the 70 pound box of stones and the turning of the Archimedes screw. Perhaps Bessler included some kind of bath or reservoir of lubricant around each bearing during the endurance test to maintain sufficient lubrication during the endurance test.