The Zij of Habash al-Hasib

An astronomical handbook associated with Habash al-Hasib, combining tables, parameters and computation within a Ptolemaic framework. Charette distinguishes this surviving zij from early works in Indian and Persian traditions. Not every occurrence of zij in a bibliography necessarily names this same text ³.

Charette argues that Mumtahan, Mamuni, Dimashqi and Arabi name one Ptolemaic work, connecting Arabi with the Hijra calendar. TDV discusses titles and relationships through Salih Zeki and manuscript studies, not a comprehensive matching exercise performed here. We keep one work record for this context rather than creating duplicate books from each name ^{4 5}.

The early Sindhind zij and the small or Shah zij are described in a different context. Similar genre labels must not erase differences of model and career phase. A title transmitted in a catalogue does not guarantee a surviving text or identity between witnesses ^{6 7}.

Charette reads the introduction as a programme to revise mumtahan observations after Ma'mun's death, with observations of Sun, Moon and planets. Dates849,860and868 and an obliquity from868/869 support his post869 completion argument. This is modern scholarship's reasoning, not a colophon we inspected. No single observation date becomes every chapter's composition year ⁸.

The account describes auxiliary jadwal al-taqwim tables, computational procedures and revised parameters within a Ptolemaic framework. The shadow-table record connects with this broad programme through TDV's description, not by inserting our modern school example into a zij cell or naming an unverified folio ^{9 10}.

Charette distinguishes an Istanbul witness closer to the original from a Berlin recension with later material; TDV discusses Yeni Cami and other manuscript evidence. Different witnesses are not treated as identical images. Scholarship places Ibn Iraq and al-Biruni in reception and Ibn Yunus in criticism of some values: influence includes examination and correction ^{11 12}.

Neither manuscripts, Debarnot's survey nor every listed reference was read here. Charette's2007 publication-status statement remains dated to its source, not a declaration about publication today. This is a complete introduction within the sources actually read, not a new edition or universal priority certificate for every table.