A Visual Imprint of Moving Air:
Prompted by an archival finding from the laboratory of Franz Max Osswald, Switzerland's first academic expert in applied acoustics, Sabine von Fischer explores the schlieren technique for photographing sound in sectional models. A Visual Imprint of Moving Air: Methods, Models, and Media in Architectural Sound Photography, ca. 1930 examines how images were used to communicate findings in the emerging discipline of architectural acoustics. In Osswald's persistent experiments in visualizing the invisible phenomena of sound, the social, the technical, and the aesthetic were inseparable. Using photography, Osswald adhered to the paradigm of mechanical objectivity, yet his visual experimenting with phenomena of spatial sound possibly demonstrates an awareness that the senses cannot be excluded from scientific methods. The shadows of moving air in the sound photographs make claims toward their scientific authority, their aesthetic appeal, and their social function as expert tools.