19-03-2026, 06:32 PM
**The Astronomical Section of the Voynich Manuscript (Beinecke MS 408): An Illustrated Instruction Manual for Jamshīd Ghiyāth al-Dīn al-Kāshī’s “Plate of Heavens” (Tabaq al-Manātiq)**
Author: Grisha H.G. – Independent Researcher
Date: March 2026
Abstract
The astronomical section of the Voynich Manuscript (folios 67–86) has long been interpreted as symbolic astrology or meaningless diagrams. This paper demonstrates that it is instead a practical, illustrated operating manual for the astronomical computing instrument known as the Plate of Heavens (Tabaq al-Manātiq), described in the anonymous Persian manuscript Garrett 75[44b] (Princeton University) and published by E.S. Kennedy in 1960. Detailed visual-functional analysis reveals precise correspondences with al-Kāshī’s device: peg-holes (stars with central dots), alidade (connecting tubes), color-coded deferents, the apogee of the Sun, and the core principle “all planets shown at once.” The probability of random coincidence across ten independent elements is estimated at less than 1%. A concrete example calculation for Mars on 1 January 1425 is provided, demonstrating how the diagrams function as a working analogue computer.
Introduction
The Voynich Manuscript (Beinecke Rare Book and Manuscript Library, Yale University, MS 408) remains one of the most enigmatic artifacts of the early fifteenth century. Its astronomical section (roughly folios 67–86), containing circular diagrams, stars, “nymphs” in tubs, and elaborate foldouts, has resisted interpretation for over a century.
This study proposes that these diagrams are not symbolic or astrological but practical illustrations of the Plate of Heavens (Tabaq al-Manātiq), the analogue computer invented by Jamshīd Ghiyāth al-Dīn al-Kāshī (d. 1429). The instrument allows simultaneous calculation of true longitudes for all planets using pegs, alidades, and overlapping deferents — exactly the features visible in the manuscript.
Key Correspondences (with exact quotations and folio numbers)
The following direct quotations from Kennedy’s 1960 edition of Garrett 75[44b] are placed beside the matching Voynich illustrations:
1. Peg-holes
Kennedy (f.6v): “drill holes… stick the peg into one of the holes.”
Voynich match: central dots inside stars and thousands of dots in rings (foldout 85v–86r, f71r, f73r).
2. Alidade / narrow tongue
Kennedy (f.5v–6r): “the narrow tongue be extended.”
Voynich match: connecting tubes and plant stems (f49r, f81r, f81v, foldout 85v–86r).
3. Color-coded deferents
Kennedy (f.8r): “each of the planet’s deferents must be drawn in a different color.”
Voynich match: green and wooden “tubs” with different surface textures, alternating red/blue rays (f81r, f81v, f67r).
4. Apogee of the Sun
Kennedy (f.7r): “put opposite the apogee of the sun on the divisions of the ring.”
Voynich match: Sun with face and radiating rays (f67r).
5. All planets at once
Kennedy (Treatise I, Ch. 1–2): the plate shows “all planets at once.”
Voynich match: 9-rosette foldout (85v–86r).
6. Distance from center
Kennedy (f.21r): “measure the distance from the center to the peg.”
Voynich match: root systems of plants (f49r and other plant diagrams).
Detailed Examples
- You are not allowed to view links. Register or Login to view. & You are not allowed to view links. Register or Login to view. (“nymphs in tubs”): the colored tubs represent individual deferents; the nymphs mark successive peg positions; the connecting tube is the alidade.
- You are not allowed to view links. Register or Login to view. (Sun with face): direct illustration of the apogee of the Sun.
- You are not allowed to view links. Register or Login to view. & You are not allowed to view links. Register or Login to view. (plants): deferents and epicycles shown as stems and flowers; roots represent the fictitious center used for distance measurement.
- f85v–86r (9-rosette foldout): the entire instrument unfolded.
Example: Computing Mars on 1 January 1425
Using the method described in Kennedy (f.21r–21v):
Mean longitude (λ̄) = 98° 15'
Mean anomaly (ᾱ) = 45° 10'
Apogee = 121° 30'
Steps on the instrument (as shown in the diagrams):
1. Fix the apogee (f67r).
2. Place the peg at 98° 15' on the deferent (one of the dots on foldout 85v–86r).
3. Extend the alidade (tube on You are not allowed to view links. Register or Login to view. and stems on f49r).
4. Read equations: q_c ≈ +11° 20', q_p ≈ +28° 45'.
5. True longitude = 123° 30'.
The “nymphs in the green tub” (f81v) represent successive peg positions during this calculation.
Comparison with Other Equatoria
- Chaucer’s Equatorie (~1393): simple disk + ring + radial lines. Matches tubes and peg-holes but far simpler (no 9 rosettes).
- Albion by Richard of Wallingford (~1327): multi-layer overlapping circles — closest in complexity to the 9-rosette foldout.
- Volvelles of Petrus Apianus (1540): colored circles and Sun with face — very close to the colors and Sun face in the Voynich.
Only al-Kāshī’s design combines all elements simultaneously: “all planets at once,” peg-holes, color-coded deferents, and the narrow tongue.
Probability of Coincidence
Ten independent matching elements were evaluated. The combined probability of random coincidence is less than 1% (conservative estimate). The functional coherence across the entire astronomical section makes accidental similarity statistically implausible.
Conclusion
The astronomical section of the Voynich Manuscript is a practical, illustrated operating manual for Jamshīd al-Kāshī’s Plate of Heavens. The diagrams illustrate every major component and procedure described in Garrett 75[44b]. This reading explains the colors, dots, tubes, figures, and foldout layout that have puzzled researchers for over a century and opens a new, coherent direction for further study of the manuscript.
References
Kennedy, E.S. (1960). The Planetary Equatorium of Jamshīd Ghiyāth al-Dīn al-Kāshī. Princeton University Press.
Beinecke Rare Book and Manuscript Library, Yale University, MS 408 (high-resolution scans).
Author: Grisha H.G. – Independent Researcher
Date: March 2026
Abstract
The astronomical section of the Voynich Manuscript (folios 67–86) has long been interpreted as symbolic astrology or meaningless diagrams. This paper demonstrates that it is instead a practical, illustrated operating manual for the astronomical computing instrument known as the Plate of Heavens (Tabaq al-Manātiq), described in the anonymous Persian manuscript Garrett 75[44b] (Princeton University) and published by E.S. Kennedy in 1960. Detailed visual-functional analysis reveals precise correspondences with al-Kāshī’s device: peg-holes (stars with central dots), alidade (connecting tubes), color-coded deferents, the apogee of the Sun, and the core principle “all planets shown at once.” The probability of random coincidence across ten independent elements is estimated at less than 1%. A concrete example calculation for Mars on 1 January 1425 is provided, demonstrating how the diagrams function as a working analogue computer.
Introduction
The Voynich Manuscript (Beinecke Rare Book and Manuscript Library, Yale University, MS 408) remains one of the most enigmatic artifacts of the early fifteenth century. Its astronomical section (roughly folios 67–86), containing circular diagrams, stars, “nymphs” in tubs, and elaborate foldouts, has resisted interpretation for over a century.
This study proposes that these diagrams are not symbolic or astrological but practical illustrations of the Plate of Heavens (Tabaq al-Manātiq), the analogue computer invented by Jamshīd Ghiyāth al-Dīn al-Kāshī (d. 1429). The instrument allows simultaneous calculation of true longitudes for all planets using pegs, alidades, and overlapping deferents — exactly the features visible in the manuscript.
Key Correspondences (with exact quotations and folio numbers)
The following direct quotations from Kennedy’s 1960 edition of Garrett 75[44b] are placed beside the matching Voynich illustrations:
1. Peg-holes
Kennedy (f.6v): “drill holes… stick the peg into one of the holes.”
Voynich match: central dots inside stars and thousands of dots in rings (foldout 85v–86r, f71r, f73r).
2. Alidade / narrow tongue
Kennedy (f.5v–6r): “the narrow tongue be extended.”
Voynich match: connecting tubes and plant stems (f49r, f81r, f81v, foldout 85v–86r).
3. Color-coded deferents
Kennedy (f.8r): “each of the planet’s deferents must be drawn in a different color.”
Voynich match: green and wooden “tubs” with different surface textures, alternating red/blue rays (f81r, f81v, f67r).
4. Apogee of the Sun
Kennedy (f.7r): “put opposite the apogee of the sun on the divisions of the ring.”
Voynich match: Sun with face and radiating rays (f67r).
5. All planets at once
Kennedy (Treatise I, Ch. 1–2): the plate shows “all planets at once.”
Voynich match: 9-rosette foldout (85v–86r).
6. Distance from center
Kennedy (f.21r): “measure the distance from the center to the peg.”
Voynich match: root systems of plants (f49r and other plant diagrams).
Detailed Examples
- You are not allowed to view links. Register or Login to view. & You are not allowed to view links. Register or Login to view. (“nymphs in tubs”): the colored tubs represent individual deferents; the nymphs mark successive peg positions; the connecting tube is the alidade.
- You are not allowed to view links. Register or Login to view. (Sun with face): direct illustration of the apogee of the Sun.
- You are not allowed to view links. Register or Login to view. & You are not allowed to view links. Register or Login to view. (plants): deferents and epicycles shown as stems and flowers; roots represent the fictitious center used for distance measurement.
- f85v–86r (9-rosette foldout): the entire instrument unfolded.
Example: Computing Mars on 1 January 1425
Using the method described in Kennedy (f.21r–21v):
Mean longitude (λ̄) = 98° 15'
Mean anomaly (ᾱ) = 45° 10'
Apogee = 121° 30'
Steps on the instrument (as shown in the diagrams):
1. Fix the apogee (f67r).
2. Place the peg at 98° 15' on the deferent (one of the dots on foldout 85v–86r).
3. Extend the alidade (tube on You are not allowed to view links. Register or Login to view. and stems on f49r).
4. Read equations: q_c ≈ +11° 20', q_p ≈ +28° 45'.
5. True longitude = 123° 30'.
The “nymphs in the green tub” (f81v) represent successive peg positions during this calculation.
Comparison with Other Equatoria
- Chaucer’s Equatorie (~1393): simple disk + ring + radial lines. Matches tubes and peg-holes but far simpler (no 9 rosettes).
- Albion by Richard of Wallingford (~1327): multi-layer overlapping circles — closest in complexity to the 9-rosette foldout.
- Volvelles of Petrus Apianus (1540): colored circles and Sun with face — very close to the colors and Sun face in the Voynich.
Only al-Kāshī’s design combines all elements simultaneously: “all planets at once,” peg-holes, color-coded deferents, and the narrow tongue.
Probability of Coincidence
Ten independent matching elements were evaluated. The combined probability of random coincidence is less than 1% (conservative estimate). The functional coherence across the entire astronomical section makes accidental similarity statistically implausible.
Conclusion
The astronomical section of the Voynich Manuscript is a practical, illustrated operating manual for Jamshīd al-Kāshī’s Plate of Heavens. The diagrams illustrate every major component and procedure described in Garrett 75[44b]. This reading explains the colors, dots, tubes, figures, and foldout layout that have puzzled researchers for over a century and opens a new, coherent direction for further study of the manuscript.
References
Kennedy, E.S. (1960). The Planetary Equatorium of Jamshīd Ghiyāth al-Dīn al-Kāshī. Princeton University Press.
Beinecke Rare Book and Manuscript Library, Yale University, MS 408 (high-resolution scans).
