04-01-2026, 10:54 AM
(This post was last modified: 04-01-2026, 11:03 AM by Jorge_Stolfi.)
Hallucinations of Galactic proportions! Or maybe just of a little pond...
On f68v3, the "Spiral Nebula" diagram:
This image is a mosaic of clips from page f68v3, the "Spiral Nebula" page.
The clips cover the perimeter of the wavy ("nebuly") closed line between the outer text ring and the central "T-O map". The region between the latter and the wavy line contains a couple dozen stars. In spite of these stars, that area is traditionally called the "pond" (possibly because of the mottled blue paint, that recalls water more than sky).
This wavy line can be split into eight sections, such that the midpoints of the "fingers" (waves) in each section lie approximately on a straight line. Thus the shape of the pond is roughly an irregular octagon, shown by the orange lines in the image above. The lengths of the sides vary from ~22 mm to ~55 mm, and the outer angles vary from ~12° to ~69° (compared to the 45° of a regular octagon). Clips 01-08 cover these sections in clockwise order starting from the one at ~10:30. Here is a zoom-out view:
Note that most of the fingers consist of two parallel traces, ~1 mm apart, either on the CW side of the finger or on its CCW side. The choice between the two sides changes at random places. The exceptions are noted below.
This page underwent at least one comprehensive restoration pass (Rt1) that retraced almost all the text and a large part of the diagram. On the BL 2014 images, these traces are medium to dark yellowish brown and rather broad (~0.4 mm).
The original (Rt0) traces, narrower and quite faint, survive as the tips of some tails and a few portions of the spiral arms, annotated below. Unfortunately Rt1 outline traces with reduced pressure may look like Rt0 traces. Outside these clips, Rt0 traces survive also as most of the mechanical circles, and a few bits on the star outlines.
Outside of these clips there is evidence suggesting a third round of retracing, with even broader traces than Rt1 (~0.6 mm) and darker and slightly more reddish ink. This pass retraced some of the text, but apparently had little impact on the nebuly line.
(A1,A2,A3) The distal halves of these tails are Rt0.
(B1,B2,B3,B4,B5,B6,B7) Possible original (Rt0) traces on the figure.
(C1,C2,C3,C4) Fingers without double trace.
(D1) Finger with double trace on both sides.
(E1) This finger may be normal, but the image is heavily distorted by the fold on the vellum.
(F1) Incorrect tracing of the arm, and painting of the finger's side. (F2) This detail is hard to parse. It could be an incorrect Rt1 trace that looks like Rt0 due to reduced pressure. (F3) Outline garbled by Rt1. (F4) This whole finger (both traces) may have been added by the Retracer. Note that it does not connect properly to the previous one or to the spiral arm. It is also unpainted, suggesting that the retracing happened after the painting. (F5) Outline garbled by Rt1. (F6) Malformed finger, possibly because of the difficulty of drawing/retracing over the fold.
Discussion
The diagram has eight "arms" -- curved bands of text that start at the outer text ring and spiral inwards. Four of them end at the edge of the pond, as if they were channels leading into it or out of it. They alternate with four other arms that cross the edge of the pond and terminate at the inner text ring.
Apparently the plan was for each of these bands to end or cross the wavy line at a vertex of the octagon, each taking the place of a finger. However in a few cases the arm crosses the octagon in the middle of a side, and its relation with the fingers may be confusing, as can be seen on the clips above.
The double traces on the fingers give the impression that the pond is cut out of a thick plate, or is sunken or raised from the surroundings, with a sharp vertical step of uniform height all around.
However, the rendering of this "cut" or "step" is geometrically inconsistent, so that the bottom edge is often visible or invisible where it should not be. All the fingers of the pond, except 4, have double tracing either on the CW side or on the CCW side, randomly. Sometimes this double tracing extends a bit over the "fingertip" and/or a bit along the bottom of the gap between fingers. One finger has double tracing on both the CW and CCW sides (but not at the tip), and some fingers are partly covered by the spiral arms, so that their double tracing would not be visible. Anyway, if the pond is meant to be flat and seen face-on, this cut or step should not be visible anywhere.
Some of these rendering mistakes could be due to the notorious artistic incompetence of the original Scribe. However, some of the errors can be best explained as the result of retracing and "improvements" by a Retracer who did not understand the drawing, and therefore must have been distinct from the original Scribe.
As usual, every statement above is implicitly prefixed with "I believe that" or "my best guess is that".
All the best, --stolfi
On f68v3, the "Spiral Nebula" diagram:
This image is a mosaic of clips from page f68v3, the "Spiral Nebula" page.
The clips cover the perimeter of the wavy ("nebuly") closed line between the outer text ring and the central "T-O map". The region between the latter and the wavy line contains a couple dozen stars. In spite of these stars, that area is traditionally called the "pond" (possibly because of the mottled blue paint, that recalls water more than sky).
This wavy line can be split into eight sections, such that the midpoints of the "fingers" (waves) in each section lie approximately on a straight line. Thus the shape of the pond is roughly an irregular octagon, shown by the orange lines in the image above. The lengths of the sides vary from ~22 mm to ~55 mm, and the outer angles vary from ~12° to ~69° (compared to the 45° of a regular octagon). Clips 01-08 cover these sections in clockwise order starting from the one at ~10:30. Here is a zoom-out view:
Note that most of the fingers consist of two parallel traces, ~1 mm apart, either on the CW side of the finger or on its CCW side. The choice between the two sides changes at random places. The exceptions are noted below.
This page underwent at least one comprehensive restoration pass (Rt1) that retraced almost all the text and a large part of the diagram. On the BL 2014 images, these traces are medium to dark yellowish brown and rather broad (~0.4 mm).
The original (Rt0) traces, narrower and quite faint, survive as the tips of some tails and a few portions of the spiral arms, annotated below. Unfortunately Rt1 outline traces with reduced pressure may look like Rt0 traces. Outside these clips, Rt0 traces survive also as most of the mechanical circles, and a few bits on the star outlines.
Outside of these clips there is evidence suggesting a third round of retracing, with even broader traces than Rt1 (~0.6 mm) and darker and slightly more reddish ink. This pass retraced some of the text, but apparently had little impact on the nebuly line.
(A1,A2,A3) The distal halves of these tails are Rt0.
(B1,B2,B3,B4,B5,B6,B7) Possible original (Rt0) traces on the figure.
(C1,C2,C3,C4) Fingers without double trace.
(D1) Finger with double trace on both sides.
(E1) This finger may be normal, but the image is heavily distorted by the fold on the vellum.
(F1) Incorrect tracing of the arm, and painting of the finger's side. (F2) This detail is hard to parse. It could be an incorrect Rt1 trace that looks like Rt0 due to reduced pressure. (F3) Outline garbled by Rt1. (F4) This whole finger (both traces) may have been added by the Retracer. Note that it does not connect properly to the previous one or to the spiral arm. It is also unpainted, suggesting that the retracing happened after the painting. (F5) Outline garbled by Rt1. (F6) Malformed finger, possibly because of the difficulty of drawing/retracing over the fold.
Discussion
The diagram has eight "arms" -- curved bands of text that start at the outer text ring and spiral inwards. Four of them end at the edge of the pond, as if they were channels leading into it or out of it. They alternate with four other arms that cross the edge of the pond and terminate at the inner text ring.
Apparently the plan was for each of these bands to end or cross the wavy line at a vertex of the octagon, each taking the place of a finger. However in a few cases the arm crosses the octagon in the middle of a side, and its relation with the fingers may be confusing, as can be seen on the clips above.
The double traces on the fingers give the impression that the pond is cut out of a thick plate, or is sunken or raised from the surroundings, with a sharp vertical step of uniform height all around.
However, the rendering of this "cut" or "step" is geometrically inconsistent, so that the bottom edge is often visible or invisible where it should not be. All the fingers of the pond, except 4, have double tracing either on the CW side or on the CCW side, randomly. Sometimes this double tracing extends a bit over the "fingertip" and/or a bit along the bottom of the gap between fingers. One finger has double tracing on both the CW and CCW sides (but not at the tip), and some fingers are partly covered by the spiral arms, so that their double tracing would not be visible. Anyway, if the pond is meant to be flat and seen face-on, this cut or step should not be visible anywhere.
Some of these rendering mistakes could be due to the notorious artistic incompetence of the original Scribe. However, some of the errors can be best explained as the result of retracing and "improvements" by a Retracer who did not understand the drawing, and therefore must have been distinct from the original Scribe.
As usual, every statement above is implicitly prefixed with "I believe that" or "my best guess is that".
All the best, --stolfi