This talk examines the role of astronomical instrumentation in the transmission of mathematical knowledge within the Islamic world between the ninth and nineteenth centuries based on two main sources: extant instruments and texts. Astronomical instruments such as astrolabes and celestial globes are important information sources for they provide details on the level of knowledge, arts, and craftmanship of its time as well as traces of long-standing instrument making traditions. The engravings, parts, and types of instruments allow us to make connections between different regions and periods. Texts on instruments are also, if not more, important on mapping the transmission of knowledge. Dissemination of certain treatises on making or using instruments made the know-how widespread in the Islamic world. These texts carry ownership records, margin notes, copying information, and other relevant data that help us trace the tradition backwards. Although mapping the transmission of scientific knowledge has its challenges, detailed examination of texts and instruments together can provide a clear route. Moreover, these studies could prove important for understanding the attitude of the Islamic world towards science between the ninth and nineteenth centuries.