Ok, after some weird related dreams here is
one last explanation.
There are more intersections of lines in the
drawing. Even more than I draw, however
most of them intersect with other circles
from the arch. So there is the small purple
circle, going through the eye of Guarino and
through the book. Call that C_0
This smallest circle touches the green, most
outer complete arc - circle from the arch.
That is also the exact point where most lines
The C_0 diameter, relates to all the other big
circles and provides us with ratios.
For example: Call the smallest most inner
big circle through the arch C_1, then dividing
C_1/C_0 = 1.41 is the square root of 2.
This circle goes through the mouth of
another student, probably who loves
the square root of 2
Call the next circle C_2 and so on.
C_2/C_0 = 1.5. That is (1+square root 4)/2
C_3/C_0 = 1.62 That is (1+square root 5)/2 = the golden ratio
This circle goes through the mouth of both
Batista and Marcello symbolizing that this
is what they talk about constantly.
C_4/C_0 =1.73 That is (1+square root 6)/2
Then we have the blue circle, C_5. That is
exactly the circle where the roof parallel
extreme lines intersect.
C_5/C_0 = 1.82 That is (1+square root 7)/2.
Roofs symbolize shelter.
Divine number 7 interpretation.
C_6 is the green circle where most lines
intersect and also C_0 intersects in one
single focal point
C_6/C_0 = 1.91, if you know what it is
then tell me.
C_7/C_0 = 2 = (1+square root 9)/2
C_8 I drew, because it has the intersection
of two roof lines. C_8/C_0 = 2.05 Maybe = (1+square root 10)/2
All the circles of the arch, enclose the book
and the heads of Marcello and Battista,
symbolizing that that is what is going on
in their heads.