Baha' al-Din Muhammad ibn Husain al-'Amili, Khulasat al-Hisab (Essentials of Arithmetic), Safavid Iran, probably dated 111[0] H / 1698 Arabic manuscript on paper with 7 lines of text per page in naskhi calligraphy in black ink, a few terms and numerous diagrams and tables of figures in red ink. Introduced by a sarlow frontispiece illuminated in gold and polychrome with lambrequin decoration surmounting a gilded cartouche. The name of the author, Baha' al-Din Muhammad, appears on the second page, and the title of the book on the following page. On the last page, a colophon again gives the author's name and the date 111[0] ?/ 1698. Several owner's stamps at the beginning of the book. Bound in brown morocco with border stamped with a vegetal frieze. 19.2 x 11.4 cm Wear, stains, small tears, a few holes, restorations, folds, handwritten notes added later, binding stained, worn, spine restored. Baha al-Din al-Amili (1547-1621) was a great mathematician, astronomer and philosopher of the Safavid period. Born in Lebanon in 1547, he emigrated to Iran as a child with his family. He soon became part of Isfahan's Muslim intellectual milieu. He is known for co-founding the Isfahan School and for his scientific research, which led him to suggest the possibility of the Earth's rotation in space. Many copies of his Khulasat al-Hisab are known. The earliest, dated 1056 H / 1646, is kept at the British Library in London (IO Islamic 1748).