The Voynich Pipes

[MarcoP]

There's an interesting turn, I began to read the latin text here (f76r):

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I had another look at the illustration you linked.
I think A and S on the wheel's spikes relate to Aequinotia and Solstitia (the left A was apparently misplaced). So the twelve long spikes mark intervals of 30 degrees corresponding to the zodiacal signs. Short marks split each sign in two, creating intervals corresponding to the 24 hours (as the text says, this is some kind of clock).
Possibly, the cross formed by the lines connecting equinox and solstice points suggested the image of the cross of Christ.