Keywords: Double-lens burning apparatus, Ehrenfried Walther von Tschirnhaus, Kieslingswalde (today Slawonice, Poland), c. 1690 - Mathematisch-Physikalischer Salon, Dresden - DSC08133.JPG en Exhibit in the Mathematisch-Physikalischer Salon Zwinger Dresden Germany This artwork is old enough so that it is in the public domain Photography was permitted in the museum without restriction 2013-12-08 07 54 52 own Daderot other versions PD-old-70 cc-zero Optical instruments in Mathematisch-Physikalischer Salon Zwinger Dresden Uploaded with UploadWizard Ehrenfried Walther von Tschirnhaus Burning glasses |