This volume contains the critical edition with English translation of a richly-illustrated Arabic treatise on the construction of over one hundred various astronomical instruments, many of which are otherwise unknown to specialists. It was composed by Najm al-Dīn al-Misrī, a rather shadowy figure, in Cairo ca. 1330. The edition is accompanied by a detailed technical and historical commentary, which is framed as a self-standing essay on Islamic mathematical instrumentation. While this essay/commentary is mainly based on Najm al-Dīn's treatise, it also benefits from the consultation of a large number of previously unstudied manuscripts, and includes a discussion of all relevant sources from the period 800-1500.