I noticed that the number of blocks in each concentric ring is the same.

For some reason I thought that the number of blocks was increasing.

Anyway, this configuration creates a spiral if you connect the vertices of the squares. There are certainly a bunch of spirals in the book.

Whether this has any meaning...I was looking for something to suggest the number of "notches" on a wheel cypher.

Any guess on how many blocks are intended? I would guess around 32...