Rongorongo

The corpus is a set of wooden objects: flat tablets, a staff, two reimiro pectorals, a birdman figure, a snuff box made from a cut-up tablet, and a few fragments. Barthel lettered 24 of them A to X in 1958; the Paris snuff box (Y) and the Poike palimpsest (Z) were added later⁠[2]⁠[3]. The holders are the Congregation of the Sacred Hearts in Rome (A Tahua, B Aruku Kurenga, C Mamari, D Échancrée), the Museo Nacional de Historia Natural in Santiago (G, H, I the Staff, Z), the British Museum (J, K, L), the Weltmuseum Wien (M, N), the Ethnologisches Museum Berlin (O), the Kunstkamera in St Petersburg (P, Q), the Smithsonian (R, S), the Bishop Museum in Honolulu (T, U, V, W), the American Museum of Natural History (X), a private collection (F) and a Paris museum (Y)⁠[1]. The Keiti tablet (E) was destroyed in 1914⁠[1].

Wood identifications by Orliac found most tablets to be Thespesia populnea (Pacific rosewood), a tree that grew on the island, rather than the toromiro of island tradition; a few are of Podocarpus (yellowwood), ash or driftwood⁠[13]⁠[1]. The Berlin tablet is Thespesia and so was not driftwood⁠[12]. The glyphs were cut with sharp points, probably obsidian flakes and shark teeth, after sketching, and show scribal corrections⁠[14]. Lines run in reverse boustrophedon: the reader begins at the bottom left, reads left to right, then turns the tablet to read the next line⁠[2].

Three editions matter. Barthel's 1958 Grundlagen published drawings and the glyph catalogue; Fischer's 1997 book redrew the corpus; Horley's 2021 volume gives new tracings from the originals, casts and photographs⁠[2]⁠[15]⁠[9]. A web viewer at kohaumotu.org places Barthel's and Fischer's transcriptions side by side in Barthel's number encoding, and is the only machine-readable version of the texts that exists⁠[16]. A 3D model of the Échancrée tablet, from photogrammetry and structured-light scanning, is in a public viewer⁠[10].

The glyphs are a system, not decoration. The same compound glyphs recur across tablets held on different continents, repeated phrases appear in several texts, and the glyphs are cut in a consistent direction and orientation⁠[17]⁠[2]. Pozdniakov's reanalysis of the best-preserved texts merged Barthel's variants and ligatures and found that 52 basic glyphs account for 99.7 per cent of all glyph occurrences, and that the frequency distribution of these glyphs resembles that of syllables in the Rapanui language, which he took as evidence that the script could be syllabic⁠[8]. Barthel's own catalogue, with about 600 numbers, is regarded as imprecise, with inconsistencies in what counts as a variant⁠[3].

One passage has an agreed function. On side a of the Mamari tablet a sequence of 29 or so crescent glyphs with attached signs was recognised by Barthel as a lunar calendar; Guy showed its structure, with groups of nights marked by "heralding" sequences and a rule that could insert intercalary nights to keep the 28-night month in step with the moon⁠[6]⁠[18]. The calendar can be described but not read, and no other passage has been matched to any known content. A repetitive run on the Small Santiago tablet has been read since 1957 as a genealogy, a plausible but unconfirmed suggestion⁠[19].

The dating is now partly empirical. Four tablets in Rome were radiocarbon dated in 2024 on cellulose from the wood: three fall in the 1800s, one in 1493 to 1509⁠[11]. The Berlin tablet dates to about 1830 to 1870 after adjusting for the ethnographic record of its use⁠[12]. Every direct date is a date for the wood, not the carving.

Four positions are live on what rongorongo is. The first is that it is glottographic writing, probably logosyllabic or syllabic, recording the Rapanui language; the evidence is the structured repetition, the 52-glyph inventory and its syllable-like frequency profile, and the genealogy and calendar passages⁠[8]⁠[19]. The second is that it is proto-writing or a mnemonic system that cued chants without encoding them phonetically, a view that fits the failure of every phonetic reading and the stylised pictorial glyphs⁠[5]. The third is Fischer's specific reading as procreation chants, which has failed its tests⁠[15]⁠[8]. The fourth is a set of outsider proposals linking the glyphs to the Indus script or other distant systems, which no specialist accepts⁠[5].

On origin, two readings compete. One holds that the system was invented on the island before 1722, which the 1493 to 1509 wood date supports if the wood was carved soon after it grew⁠[11]. The other holds that it was inspired by the Spanish annexation ceremony of 1770, at which islanders "signed" a document, and so is an eighteenth-century invention; this fits the nineteenth-century dates of every other dated tablet and leaves the early date to be explained as old wood or driftwood carved later⁠[11]⁠[12].

The origin question needs direct dates on more tablets, ideally with the carving dated rather than the wood, which would mean dating the outermost rings or any organic residue in the cuts; Wieczorek has called for all tablets to be dated⁠[11]⁠[12]. The writing question needs an open, sign-level corpus built on Horley's tracings and the 3D models rather than on Barthel's codes, so that inventory, positional statistics and repeated-phrase alignment can be re-run and compared with Rapanui chants and with null corpora⁠[9]⁠[10]⁠[8]. A reading would be settled only by a proposal that reads every attested variant of the Mamari calendar and the genealogy run in Rapanui, with sign values that hold across the whole corpus, and that predicts the content of a passage before it is checked⁠[6]⁠[19].