Abstract

In this article the author analyzes a fifteenth-century Arabic reform of the Ptolemaic model for Mercury. The author of the reform was the Central Asian Al al-D who, in his youth, had been instructed in the mathematical sciences by none other than the famous Central Asian monarch Ulugh Beg (1394 has been yet identified to have produced a theoretical text devoted to the criticism, let alone the reform, of the Ptolemaic mathematical planetary models. The present article on Qushji's reform of the Ptolemaic model for Mercury includes a critical first edition of Qushji's Arabic text, an English translation, and a historical and technical commentary