The transits of Venus in 1761 and 1769 appear to mark the starting point of instrumental science in the Dutch East Indies (now Indonesia). This essay examines the conditions that triggered and constituted instrumental and institutional science on Indonesian soil in the late eighteenth century. In 1765 the Reverend J. M. Mohr, whose wife had received a large inheritance, undertook to build a fully equipped private observatory in Batavia (now Jakarta). There he made several major astronomical and meteorological observations. Mohr’s (...) initiative inspired other Europeans living on Java around 1770 to start a scientific movement. Because of the lack of governmental and other support, it was not until 1778 that this offspring of the Dutch‐Indonesian Enlightenment became a reality. The Bataviaasch Genootschap van Kunsten en Wetenschappen tried from the beginning to put into effect the program Mohr had outlined. The members even bought his instruments from his widow, intending to continue his measurements. For a number of reasons, however, this instrumental program was more than the society could support. Around 1790 instrumental science in the former Dutch East Indies came to a standstill, not to be resumed for several decades. (shrink)

Ever since they began to take an interest in lens grinding, the brothers Christiaan and Constantijn Huygens searched for high-quality glass to turn in to lenses. Historical research in combination with optical measurements on preserved lenses has allowed the verificationof the lenses ground by the brothers, and also provided information on who helped them with the necessary knowledge and material.