There are several spoke-like patterns on the rosettes folio.
They could be domes, tents, water wheels (like a mill wheel), fountain cisterns, or any number of things.
A couple of them remind me of mill wheels, like this early medieval drawing (note the way the pipe and the water are drawn):
![[Image: Medieval_mill_with_overshot_wheel.png]](https://upload.wikimedia.org/wikipedia/commons/a/ac/Medieval_mill_with_overshot_wheel.png)
Wikipedia
![[Image: add_ms_42130_f181.jpg?w=608&h=342]](https://www.bl.uk/britishlibrary/~/media/bl/global/picturing%20places/add_ms_42130_f181.jpg?w=608&h=342)
British Library, The Lutrell Psalter
There are also water-lifting wheels for wells and for irrigation (also to move water out of mining sites).
For comparison to the western drawing, here is a Persian wheel:
![[Image: Bayâd-und-Riyâd1.jpg]](http://www.funci.org/wp-content/uploads/2009/01/Bayâd-und-Riyâd1.jpg)
Here's a further idea for the spoke wheels... some kind of crank mechanism... there were many different kinds of wheel-cranks in the Middle Ages and some were quite large (note that there are Ghibelline merlons):
![[Image: attachment.php?attachmentid=45055&stc=1]](http://www.vikingsword.com/vb/attachment.php?attachmentid=45055&stc=1)
![[Image: attachment.php?attachmentid=45059&stc=1]](http://www.vikingsword.com/vb/attachment.php?attachmentid=45059&stc=1)
They could be domes, tents, water wheels (like a mill wheel), fountain cisterns, or any number of things.
A couple of them remind me of mill wheels, like this early medieval drawing (note the way the pipe and the water are drawn):
Wikipedia
British Library, The Lutrell Psalter
There are also water-lifting wheels for wells and for irrigation (also to move water out of mining sites).
For comparison to the western drawing, here is a Persian wheel:
Here's a further idea for the spoke wheels... some kind of crank mechanism... there were many different kinds of wheel-cranks in the Middle Ages and some were quite large (note that there are Ghibelline merlons):