-and, “Alternately gravitating to the centre and climbing back up again." this seems obvious but is ambiguous, look for an alternative meaning which fits the words.
There are many other clues in the text but the following one is my absolute favourite and one which is a supreme example of Bessler's deviousness, containing ambiguity, apparent nonsense and absolute truth, if you can work it out. "A great craftsman would be that man who can "lightly" cause a heavy weight to fly upwards! Who can make a pound-weight rise as 4 ounces fall, or 4 pounds rise as 16 ounces fall". I understand it completely with the proviso that there are two possible outcomes either of which it can argued, he meant but which hands-on building will resolve. There are other translations available but I like this one the best and they are each decipherable in the same way.