Jaridat al-durar wa-kharidat al-fikar

Jaridat al-durar wa-kharidat al-fikar is a zij by Taqi al-Din ibn Ma'ruf, described by TDV as a small work containing tables based on decimal fractions. Ihsan Fazlioglu's biography explains its place in applying decimal arithmetic to trigonometry and astronomy. This description uses scholarship actually read, not a purported inspection of a Jarida manuscript ^{2 1}.

A zij is a tool for calculation and tables, not solely descriptive writing about the sky. Fazlioglu discusses decimal fractions in trigonometric functions, tangent and cotangent tables, and decimal fractional degrees and calculations in the Jarida and Tashil zij al-ashariyya. He also retains a fixed-star-table exception in the description of decimal tables. That qualification belongs to the definition, rather than being an inconvenient detail to remove ¹.

This is the particular contribution linked to the book. It does not mean every decimal fraction began here, or that decimal representation determines an astronomical model's correctness. Notation, measurement and approximation are connected but distinct questions.

Taqi al-Din worked in teaching and judicial service in Egypt and later astronomy in Istanbul, benefiting from books, instruments and learning networks described by Fazlioglu and TDV. Fazlioglu connects his arithmetic with al-Kashi's work and the Samarqand school. The book therefore belongs within a long tradition of computation and observation, not isolation from predecessors ^{3 4}.

The reading used here does not establish an exact composition date or precise writing location. Neither observatory construction, the author's death nor a modern study's publication supplies a book date without evidence. Fazlioglu states that his books were written in Arabic; the modern translation's language and history must remain separate from composition ⁵.

Sidrat muntaha al-afkar concerns correcting Ulugh Beg's zij, with functions described by Fazlioglu as sexagesimal. The Jarida is discussed in a decimal context. Tekeli's inspected article compares the Sidra with Copernicus: its diameter120, radius60 and sine definition are not values extracted here from the Jarida ^{6 7}.

Different books by one author cannot be collapsed. Likewise, an unfinished observational programme does not alone establish that every book remained a draft. Each work has its own purpose, extent, chronology and witnesses.

TDV records Remzi Demir's study of the work in a1991 dissertation and publication of that study with a Turkish translation in2000 as Takiyyuddin'de Matematik ve Astronomi. This is reception information from the source read, not an edition we inspected page by page ².

A title in a bibliography does not authorize attributing every sentence to a book one has not read. The data preserve its name and a known route to the text without supplying page numbers or manuscript shelfmarks not verified in this run.

This record does not reproduce a historical table: no assumed radius, guessed row spacing or computer-generated cells presented as transcription. The contribution page's examples are explicitly modern teaching examples. TDV describes the author's verbal decimal places without the modern separator, so contemporary typesetting cannot certify priority for a symbol ⁸.

The associated image is a modern2007 triangle, not a Jarida folio. It helps readers distinguish side, angle and ratio; it does not document the author's handwriting or arrangement of manuscript tables ⁹.

Fazlioglu's complete biography, TDV's arithmetic discussion and third work, and specified passages of Tekeli for comparison with the Sidra were read. This is not a full-text reading or manuscript collation. The limits belong within the book's description, not as permission to invent what has not been seen ^{1 2 10}.