Teaching by means of light. The optical lantern in Belgian schools, 1880-1940

Long before the introduction of PowerPoint, slide shows with projected images were already an important means of educational knowledge transfer. This doctoral dissertation engages with the first use of slide projection in schools by providing a comprehensive overview of the introduction, appropriation and daily use of the so-called optical lantern in Belgian classrooms from the 1880s to the mid-20th century. Based on the analysis of a broad selection of source materials from a wide range of archives and libraries, it shows how different actors, but especially pedagogues and teachers, together managed to transform the device into a widely used teaching aid in Belgian education. It also sheds light on the ways in which teachers created their own narratives when using the medium, taking advantage of its typical flexibility to adapt slides and slide sets to their specific teaching contexts and ideologies. As it turns out, religion was an important factor in the introduction and use of a new medium such as the optical lantern. Due to the flexibility of the medium, Catholic teachers could align the narratives presented by their slides with their Catholic worldview. From the early 20th century, both Catholics, Liberals, and local governments began establishing extensive slide libraries that played an indispensable role in supplying schools with the slides they used. As a result, the distribution of slides in Belgium was clearly divided along ideological lines. Finally, this dissertation also explores what teachers hoped to achieve by using the optical lantern in their lessons: by selecting and creating slides and combining them into series, they hoped to capture their students' attention, take them on virtual journeys around the world, show them exactly what they wanted them to see, and teach them how to observe. As it turns out, teachers and policymakers instrumentalised the allure of the optical lantern to prepare Belgian pupils for their future roles as virtuous citizens by showing them slide sets depicting the historical Belgian struggle for independence, the beauty of their country and its industry, as well as the Belgian colonial endeavour in Congo. All in all, then, this dissertation shows how teachers throughout the late nineteenth and early twentieth centuries effectively integrated the medium into usually rigid educational practices. Thus, they designed new ways of teaching that reshaped teaching practices. In the form of PowerPoint and other software,