The research project "Projecting Knowledge: The Magic Lantern as a Tool for Mediated Science Communication in the Netherlands, 1880-1940" aimed write the history of the lantern lecture in the Netherlands. Its sub-project "Science for People" focused on the public format of the lantern lecture, organized outside academic environments, for a variety of adult audiences, and with the goal of transmitting some sort of knowledge. This was the premise for this dissertation, which meant to be a first survey into this historical phenomenon guided by the main question: How was public knowledge transmission and science communication mediated through the optical lantern in illustrated lectures organized in the Netherlands between 1880 and 1940 in the Netherlands, what subjects were treated, which audiences were addressed and what different types of speakers are to be distinguished? This research was largely based on primary sources such as newspapers, periodicals and other archival material, including correspondence, personal notebooks, or associations’ newsletters. My goal was to understand how and why—as well as what, who, and where—historical stakeholders engaged in this cultural practice, and exactly how common was the organization of public lantern lectures to disseminate knowledge. And while this is still a largely unknown cultural practice in historical scholarship, this research has shown that, particularly in the first decades of the twentieth century, public lantern lectures were not only a usual occasion in Dutch social life, but a truly pervasive practice that reached a variety of audiences and was used to discuss a variety of topics from the paintings of Rembrandt to strategies to fight tuberculosis or how to care for your chickens. In fact, during the winter season, in the first decades of the twentieth century, public lantern lectures were almost a daily occurrence, organized by a myriad of associations.