De Magnetica [...] Plantarum p. 648

I earlier exhibited the magnetic clock. The first clock showed what time it was wherever you were in the world by a single movement on the circular hour-scale, by the method I have set out above in describing the magnetic clocks. The second was a glass sphere full of water, in the middle of which, in a globule representing the earth, the heliotropic material was bound in such a way that it could easily and without impediment direct itself toward the sun; and each experiment had an outstanding success, which lasted however (such is the transient state of sublunary things) but a few days, as the material was degraded by the water. So all that is still needed in such an experiment is to find a way to preserve the material from any decay; if I find this (as by God's grace I still hope to do), nothing indeed can appear to add to the excellence of this experiment. So, noting the incompleteness of this matter, and there being no way for this kind of sympathic timepiece to continue, I replaced it, in this fever of creative intelligence, with the magnetic timepiece discovered on this occasion, of the kind that I have described in my Magia Magnetica; since this constantly and perfectly showed the time night and day with no fear of decay, it excited no little admiration on the part of those who saw it, who mostly, as they did not understand the arcane method of contruction, falsely persuaded not just themselves but others too that it was done with the help of some root or other. I found this to be the most perfect of all the Sympathic Clocks. I find in the Symbola Heroica of Sylvester Petra Sancta a similar sympathic clock