Hi Steve,"In a machine such as mine, on the other hand, the motive force, the ability to move itself and drive other objects makes up the FORM of the device, iwthout which its framework is just any old heap of material, which has completely lost its essence. To cause the machine to stop requires the application of a greater external force, and can be accomplished without difficulty whenver one requesres it, e.g. for the machine's longer conservation. Such a cessation can also occur through the wearing out or breaking of the machine's part. The first is a "moral accident", the second a "material accident." As an example of the ideas I am discussin, consider the case of two samall metal spheres, one of iron and one of lead. For both of them, thier FORM consists in thier regulare sphericity. But we find, placed in a furnace, on loses its shape quicker than the other. Therefore the greater or lesser "meltability" of such spheres is not the result of "sphericalness" - common to bothe - but of the physical characteristics of the two materials. And it is this "material accident" which is the FORMAL CAUSE of the difference."
I think in this paragraph Bessler is just talking about the fact certain materials are better suited for the building of a wheel that is meant to run perpetually. In the paragraph he makes a distinction between a moral accident, when someone decides to manually "turn off" the wheel and a material accident when the materials that make up the wheel fail causing its motion to cease. IMO when he talks about the difference between how quickly a lead sphere will melt in a furnace as compared one of steel he is simply pointing out that certain materials are better suited for the construction of a PMM.
My 2c.
E