One Thousand and One Conjectures

Dated Hebrew colophons record the day a manuscript was completed, and the Jewish week and festival calendar imposed hard deadlines on scribal labour: no writing on the Sabbath, and liturgical books that were only useful if delivered before their festival. The conjecture…

Late-medieval Hebrew scribes liked to date books by chronogram — a Bible verse or pious phrase whose letters, read as numerals by gematria, encode the year. But not every year has an apt verse: some numbers spell familiar, resonant words, while others…

Hebrew books came from two channels: commissioned copies by professional scribes and copies owners made for their own use, and colophons usually say which. A commercial scribal market needs stable communities with clients, credit, and reputations, whereas an owner with a borrowed…

Paper entered Europe from the Islamic world, and Jewish communities sat astride that boundary, with correspondents, in-laws, and book-suppliers on both sides of it. The conjecture is that dated Hebrew manuscripts adopted paper systematically earlier than Latin manuscripts produced in the same…

A minority of Hebrew colophons record both when the work began and when it ended, and the database records each book's extent, so copying speed in folios per day is directly computable for a real population of medieval scribes — a measurement…

Many Hebrew colophons date a book in more than one system at once — the era of Creation, the Seleucid count, sometimes the Muslim or Christian year, plus the weekday and the week's Torah portion. Converting between these systems requires either live…

Hebrew script types are named for regions — Sephardic, Ashkenazic, Italian, Byzantine, Oriental — but expulsions kept tearing scribes loose from the landscapes their hands were named for. Because SfarData records both the script type and the actual place of copying, the…

Before a scribe wrote a line, the page was ruled, and ruling technology changed: hard point, coloured plummet, and in the Islamic world the mastara, a string-and-board template that rules a whole page in one press. Hebrew manuscripts were produced on both…

Beneath script, which a scribe can consciously adapt, lie codicological habits almost nobody thinks to change: how many leaves make a quire, how flesh and hair sides of parchment face each other, where the pricking goes. These conventions differed by region —…

Everything we know statistically about dated Hebrew manuscripts flows through colophons, and colophons live in the most dangerous real estate in a codex: the final leaves, first to be lost to wear, damp, and detached quires. Dated manuscripts are therefore not a…

The history of Hebrew books is told as a history of burnings — Paris 1242, confiscation after confiscation — and the natural assumption is that these catastrophes carved visible craters in the surviving population. Set against them is the quiet attrition that…

Two filters selected which medieval Hebrew books reached us: communities preserved what they kept using, and Christian authorities confiscated what they condemned — above all the Talmud — much of which went to binders as parchment scrap, now documented as thousands of…

Binders wanted large, stiff sheets of parchment for covers, spine-linings, and pastedowns, so the recycling channel did not sample the Hebrew book population evenly: a large-format Bible or Talmud yields useful sheets, a pocket prayer book yields little worth the knife. The…

Every synagogue needed Torah scrolls, scrolls wear out fast under liturgical use, and worn scrolls were ritually retired rather than shelved — yet scrolls carry no colophons, so the best-dated manuscript population on earth contains almost none of them, and quantitative histories…

Jewish communities dated things in two registers: ink — colophons, deeds, letters — and stone, the tombstone epitaph. Both had to choose an era, Anno Mundi or the Seleucid count among others, and eras went in and out of fashion. The conjecture…

Geniza book-lists record actual prices paid for books, and colophons occasionally record scribal fees, giving the raw material for a genuine price series of Hebrew books across centuries — something no narrative source provides. Over those same centuries paper spread and cheapened…

The Black Death killed scribes, patrons, and owners alike, and for most manuscript cultures its effect on book production is inferred rather than measured, because dated books are too few. Hebrew colophons are dense enough in the mid-fourteenth century to see the…