Every source this work relies on, refuses, or could not find — and, where the source makes a geometric claim, what happened when we tested it.
Listing the literature is easy. What is almost never done is to take a paper’s published figure, run it through an engine, and report what closes and what does not. Thirteen of the 27 entries below carry that measurement.
Mathematical
primaryBolton, N. J. and D. Nicol G. Macleod1977The Geometry of the Śrī-Yantra
Religion 7
The first modern treatment. A seven-by-seven grid construction, drawable by hand. Their framing — how many points remain free once the largest triangles are set — is the question everyone since has answered.
what we measuredTheir construction misses concurrency by 0.2229% of the construction square’s side: about ten times more accurate than the traditional method, and not exact.
in the book: ch. 9
primaryChiodo, Alessandro2021Comptes Rendus. Mathématique 359 (4), 377–397
Straightedge-and-compass construction for concurrent Śrī Yantras; the problem reduces to the Apollonius circle–line–point problem. Independently derives four degrees of freedom. The most important paper in this field, and almost nobody cites it. Note his phrasing is careful — the spherical hypothesis *would have been reinforced* by plane impossibility; he does not claim the spherical form is false.
what we measuredHis four degrees of freedom agree with Huet’s count and with ours: imposing concurrency and concentricity on five parameters leaves three free.
in the book: ch. 13 · ch. 25 · ch. 26
Theoretical Computer Science 281, 609–628 (preprint 1990)
The theorem: an under-determined problem with four real parameters admitting an infinity of solutions. Candid that his remaining parameters were fixed by aesthetic judgment. His bibliographic reconstruction — through Zimmer, Woodroffe, Campbell, Jung, Daniélou, Pott, Rawson and Renou — is the best scholarship in the field, and everyone since depends on it.
what we measuredSolving his fifth parameter from concurrency alone reproduces his published value to 7 × 10⁻⁵ — independent confirmation of his algebra. But his figure satisfies concurrency and nothing else: its concentricity residual is 4.19 × 10⁻², the largest of any figure in this library. The innermost triangle sits visibly off centre.
Huet 1990 / 2002 — concurrency 1.38e-7, concentricity 4.19e-2, 43 chambers.
in the book: ch. 2 · ch. 11
primaryKulaichev, A. P.1984Sriyantra and its Mathematical Properties
Indian Journal of History of Science 19 (3), 279–292
An eighth-degree polynomial, and the error metric this book adopts throughout — displacement at critical intersections as a percentage of R. Widely reported as having derived spherical equations. He has none, and says so himself, calling a polynomial description “doubtful”. His spherical argument is philological and dimensional, not geometric.
what we measuredHis root y_A = 0.279461220858 is reproduced exactly. His inference that the figure cannot be constructed in the plane fails on a conflation of *constructible* with *solvable in radicals* — Chiodo later constructs it.
Kulaichev 1984 — concurrency -3.58e-7, concentricity 1.18e-7, 43 chambers.
in the book: ch. 10 · ch. 26
Sriyantra — A Study of Spherical and Plane Forms
Indian Journal of History of Science 33 (3), 203–227 (from his 1993 thesis, IIT Bombay)
The source of the five-variable parameterisation b, c, d, e, g used throughout the modern literature **without attribution**. His spherical formulation in six variables is the only complete one in existence. Under-credited to the point of invisibility.
what we measuredAll seven of his Table 3 parameter sets satisfy our equations at 10⁻⁷. Two of them already satisfy the three “optimal” criteria — eight years before those criteria were proposed. One correction: his reported global optimum as h → π/2 does not survive checking; the traditional data minimises at r ≈ 20°.
Rao 1998 — plane optimum — concurrency -2.28e-7, concentricity 1.20e-7, 43 chambers.
in the book: ch. 12 · ch. 24 · ch. 26
unpublished[Anonymous]2012Śrī Chakram: Tiru-pū or Sri Pushpam, Tri-puram
Unpublished typescript, 16 December 2012; 31 pp.; circulated as a PDF. No author, publisher or place of publication stated
The source of the kuṇḍāṃśa hypothesis — that the nine apex angles are multiples of 360°/81 — which appears nowhere else and is the most interesting untested claim in the archive. Anonymous: no author, no publisher, closes with a hymn rather than a colophon, and its distinctive phrasing returns nothing on search. Its file properties name “Sri Chakra Hari_16 Dec 2012.docx”, but Hari there is Saundaryalaharī, not a person. Cannot be cited as authority; can be tested, which is what Chapter 7 does.
what we measuredThe kuṇḍāṃśa claim is put to the engine in Chapter 7 rather than repeated. Its other uses are quotation only, on points that are independently checkable. One use is indirect and flagged: at Chapter 12 it relays a comparison of C. S. Rao’s that has not been read in the original.
in the book: ch. 4 · ch. 6 · ch. 7 · ch. 9 · ch. 12
primaryTiwari, Sudarshan Raj2011Sri-Chakra: Rediscovering the Rules of its Construction from First Principles
An architect’s framing: previous work treats the diagram as occult or as abstract sacred geometry, and nobody has asked what functional objective the construction serves. Notes the requirement of 24 triple intersections.
what we measuredThe 24 triple intersections are confirmed and counted by the engine.
in the book: ch. 9 · ch. 15
unreliableSanthi, B., N. Rajesh Kumar, C. Bharathy and R. Bala Krishnan2012Generation of Divine Image — Sri Yantra
Research Journal of Applied Sciences, Engineering and Technology 4 (14), 2241–2246
Do not cite as evidence. Reproduces 60, 43 and 40 consecutive words from Tiwari as its own prose; carries Huet’s parameters and theorem under the caption “Kulaichev method”; and inherits an OCR corruption of Huet’s “that one *too*” as “that one *two*”, which establishes the direction of copying.
what we measuredReports no parameters, no residuals and no geometry. Its algorithm calls undefined primitives and its performance analysis measures milliseconds instead of accuracy, so there is nothing here to test.
in the book: ch. 15
Sanskrit sources and commentaries
primarySaundaryalaharī, verse 11with the commentary of S. S. Sastri and T. R. S. Ayyangar
Theosophical Publishing House, Adyar — commentary at p. 65
The parts list: four Śrīkaṇṭhas, five Śivayuvatīs, nine mūlaprakṛti, forty-three, eight petals, sixteen kalās, three circles, three lines. Names the nine by their **angles** — caraṇakoṇāḥ. Note the trayaś- / catuś- variant, 43 against 44.
what we measuredThe accompanying figure reverses the apex directions and contradicts the commentary’s own text — an engraving error that has propagated widely.
in the book: ch. 4
Saubhāgyavardhinī on the Saundaryalaharī
Gives the erasures as fractions of each chord: 1/16, 5/48, 1/3, 3/8, 1/3, 1/12, 1/16.
what we measuredThese are **identical** to Lakṣmīdhara’s integers once the unit is recognised as twenty-fourths of the chord — which dissolves a century-old charge that the two commentators disagree.
in the book: ch. 5
commentary on the Saundaryalaharī
Erasures as absolute units: 3, 5, —, 16, 18, 16, —, 4, 3. Also the antarbhāva triad: meru = the sixteen Nityās, kailāsa = the Mātṛkās, bhū = the Vaśinīs — with **no word about elevation**.
in the book: ch. 5 · ch. 28
primaryTantrarājatantra 6.52–541926ed. Lakshmana Shastri, with the Manoramā of Subhagānandanātha
1926, p. 116
The four Meru elevation profiles, each with its phala. The printed viviкramāt is corrupt; read tri-trikramāt with the Saubhāgyaratnākara p. 46.
what we measuredAll four profiles are implemented and selectable. None of them fixes a height: the tradition prescribes the elevation ordinally and never metrically.
in the book: ch. 28 · ch. 31
Nityotsava, p. 69
Distinguishes bhauma and mairava prastāra. States plainly that **the innermost enclosure is the highest** — against the widely-copied web accounts, which have it backwards.
in the book: ch. 28
via the Saubhāgyaratnākara p. 45
The triad bhū / ūrdhva / meru as a distinction of **relief**: incised below, raised but level, progressively raised. This is the passage Gopinatha Rao inverts.
in the book: ch. 28
Śrī Cakra Pūjā Kalpam
Sanskrit and Malayalam verses
The Kāśmīra construction method, and the 96-unit total scale giving 4 : 9 : 11 : 48.
what we measuredThe 4 : 9 : 11 : 48 proportions are the default ornament scale in the studio.
in the book: ch. 1 · ch. 5 · ch. 21
primaryVyāse devīkṛte… versein kaṭapayādi notation
Diameter 48; chords at 6, 12, 17, 20, 23, 27, 30, 36, 42; erasures 3, 4, 0, 16, 19, 16, 0, 4, 3; and the complete apex topology.
what we measuredThe apex topology is verified against the algebra for all nine triangles. The twenty-seven numbers are mutually inconsistent at 2.675% of R — the tradition’s own noise floor, and the standard against which every reconstruction in this library is judged.
The Tradition — 12 : 6 : 7 : 11 : 3 in twenty-fourths — concurrency 2.21e-2, concentricity -3.63e-3, 43 chambers.
in the book: ch. 5 · ch. 6
Setubandha, 8th viśrāma, p. 283
Names the Tantrarāja and the Gaurīyāmala as sanctioning the meruprastāra.
in the book: ch. 28
(not found)
Cited by Bhāskararāya for the Meru and by Gupta for the kūrma. Not found in any digitised form. **The single highest-value missing source for this work** — it may settle the elevation, the kūrma, or both.
in the book: ch. 28
(does not survive)
Listed among the nine Nityā-tantras by the Manoramā on Tantrarāja 1.2. A construction manual of exactly the right name. Does not survive.
in the book: ch. 28
Iconography and tradition
secondaryRao, T. A. Gopinatha1914Elements of Hindu Iconography, vol. I part ii, pp. 330–331
Use with care. The locus for the Meru’s plan being the plane figure, and for the Meru / Kailāsa / Bhū triad. But he **inverts bhū**, which in the Lakṣaṇasāgara is the flat incised form; omits Lakṣmīdhara’s meru = the sixteen Nityās; and cites no source. Huet quotes the passage verbatim, which is how the error entered Western scholarship.
what we measuredHis Plate XCVIII — a photograph of the Śṛṅgeri metal plate — is the closest thing to a physical exemplar in the literature, and the best candidate for rectified photogrammetry.
in the book: ch. 1 · ch. 28 · ch. 30
secondaryZimmer, Heinrich1926Kunstform und Yoga im indischen Kultbild
The frontispiece added by the translators is a *correct* figure; the book’s own diagrams are not, and they disagree with it. A source of much subsequent error.
in the book: ch. 2 · ch. 11
secondaryWoodroffe, John (Arthur Avalon)1914cover figure
The cover carries the **false Śrī Yantra**, with floating apexes — triangles whose vertices do not meet. Propagated through Campbell and, inverted, through Jung.
in the book: ch. 2
article 1166
Settles the orientation: five downward and four upward. His accompanying figure 28 is nonetheless a false Śrī Yantra.
in the book: ch. 1 · ch. 11
secondaryBühnemann, GudrunMandalas and Yantras in the Hindu Traditions, pp. 30–31
Collates the entire modern literature on three-dimensional Śrīcakra typology, and **reports no proportions from any author**. The word yojana does not occur in the volume. Much of the negative result — that no text gives a Meru height — rests on this collation.
in the book: ch. 29
secondaryKloetzli, Randy1985History of Religions 25 (2), 116–147
The Purāṇic inverted-cone problem. Has never met the Śrīvidyā literature, and vice versa — a connection never yet made.
in the book: ch. 31
secondaryViṣṇu Purāṇa II.2 and Bhāgavata V.16.7Mount Meru’s dimensions
Mount Meru at 84,000 yojanas high, 32,000 at the summit, 16,000 at the base — wider at the top. Wilson’s note calls it “an inverted cone”. **Incompatible with a yantra narrowing to a bindu**, and applied by nobody.
in the book: ch. 31
Six questions this work leaves open, and where an answer would have to come from. They are listed because a study that reports only what it settled is not reporting honestly.
This page links to sources; it does not reproduce them. Where a paper is genuinely open access the link goes to the publisher’s own copy. Where it is not, you will find the citation and our reading of it, and nothing else — the annotation is ours to give away, the paper is not.