How did it work? historic phonetic devices explained by coeval photographs

The early history in experimental phonetics and speech technology is featured by numerous sophisticated devices which we can study today in a number of historic collections which are located mainly at universities. In many cases, however, it is not easy to understand how these devices have been applied in an optimal way. Illustrations and historic photographs are especially helpful. The historic collection of the TU Dresden, which also includes the former devices of the Hamburg phonetician Giulio Panconcelli-Calcia, benefits from the fact that he prepared a lot of photographs which are still available in the collection. They show selected phonetic experimental equipment in function. This paper informs about the photographic part of the Dresden collection and presents some examples.