Although Ernst Mach's name is inextricably linked with Vienna and Viennese philosophy, the scientist spent his most productive years in nearby Prague. Moving there from Graz in 1867, where he had suffered from a lack of means to perform laboratory experiments,¹ Mach took up the chair of experimental physics at the University of Prague. The position promised research space and a budget for exactly the sort of experimental work Mach enjoyed. His most signal professional achievements in physics were in the area of experiment, for example in his work on establishing the Doppler effect and in photographing the shock waves of supersonic bullets, which gave us the term Mach I.