The Epistle of the Number

Title:

The Epistle of the Number

Alternative title:

אגרת המספר

Creator:

Isaac b. Solomon ibn al-Aḥdab b. Ṣaddiq Sefardi Isaac ben Solomon ben Ẓaddik al-Aḥdab 13..-1431?

Date:

16th century

Description:

Isaac b. Solomon ibn al-Aḥdab b. Ṣaddiq Sefardi's The Epistle of the Number was composed at the end of the 14th century after Isaac settled in Syracuse, Sicily, and this is the only known copy of the work. The Epistle is a translation and enlargement of the famous Talḵīṣ ʿAmal al-Ḥisāb ('A summary of the operations of calculation', 13th century) by the Moroccan Muslim mathematician Ibn al-Bannā ابن البنّاء‎ and it is especially notable in being the first known treatise in Hebrew to include extensive algebraic theories and operations. The Epistle attests novel mathematical vocabulary and enhances our linguistic understanding of the mechanisms that helped create the scientific vocabulary of Medieval Hebrew. The work proper begins on f.1v, with an explanation of how Isaac came to compose the Epistle. Book 1, arithmetical operations on integers, fractions and roots is on ff.1v–25r, and consists of three parts: part 1, arithmetical operations on integers; part 2, arithmetical operations on fractions; and part 3, arithmetical operations on the roots of expressible (rational) and inexpressible (irrational) quantities. Book 2, the rules which enable us to obtain the unknown from the given known, is on ff.27r–38v, and also consists of three parts: part 1, proportions and scales; part 2, the algebraic operations of restoration and operation; part 3, solution of problems of a practical nature by methods of algebra. The last words in part 3, on folio 38v, are 'another example', thus the manuscript is truncated. First words and headings are written in larger, bolder script; some words and the numerals in calculations are rubricated. There are tables with both Hebrew and Arabic numerals, as well as diagrams. There are occasional marginal calculations in a different hand, e.g., f.6r, as well as manicules, e.g., f.7v. Diagrams include the place-value numerical system with zero and Hindu-Arabic numerals, f.2r; various scales, ff.25v–26v; and multiplication tables of algebraic expressions, f.34v. Unrelated to the Epistle, f. 1r describes a mathematical problem, with a diagram of two birds sitting on two towers of unequal height, and referring to Elijah Mizraḥi אליה המזרחי in the last line. Various elaborate signatures and owners' marks follow in the lower half of the leaf, including the name Judah Eli יאודה עלי.Condition: Slightly affected by damp, a few pages show evidence of ink corrosion.Layout: Written in one column with 37-38 lines per page.

Language:

Hebrew

Type (Narrower):

Manuscripts

Type (Broader):

Text

Provenance:

Rustat Benefaction: bought in 1869 from H. Lipschütz Lipschütz, H. .

Medium:

Paper

Extent:

Leaf: (height: 300 mm, width: 210 mm)

Publisher:

Cambridge University Library

Rights:

Images made available for download are licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License (CC BY-NC 3.0)
This metadata is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License.

Identifier:

MS Add.492.1

Format:

Codex

Is part of:

Hebrew Manuscripts Collection

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