Treatise on drawing horary lines on horizontal, vertical, and oblique sundials

Ibn al-Majdi, Shihab al-Din Abu'l-Abbas Ahmad. Irshad al-ha'ir ila takhtit fadl al-da'ir [Guide to the Right Path for the Perplexed in Drawing (Lines) of Surplus of Turn].

No place, late 16th century CE (ca. 1000 H).

4to (150 x 202 mm). Arabic manuscript on polished paper. 114 pp., final blank leaf. Naskh script in black and occasional red ink, 17 lines, single column, text enclosed within black and red rules. Numerous charts and a few diagrams in the text. 19th century red half cloth over marbled boards.


An astronomical work on drawing horary lines on sundials, by the Egyptian mathematician and astronomer Shihab al-Din ibn al-Majdi, arranged in three parts: horizontal sundials; vertical sundials; and oblique sundials. Other copies can be found in Berlin, Cairo, Istanbul, Leiden, Rabat and Tunis; there appears to be no copy of this work in the British Library.

Marginal glosses to a few pages; several inscriptions and waqf stamps to title-page. Some waterstaining near the end with noticeable worming throughout, mainly confined to the margins. Well preserved.


Cf. GAL II, 128, 10, no. 2. B. A. Rosenfeld & E. Ihsanoglu, Mathematicians, Astronomers & Other Scholars of Islamic Civilisation and Their Works (Istanbul 2003), p. 276, no. 815.

Stock Code: BN#53810