The goal of the article is to present in short the history and character of the songs included in the so called „Prague collection“, the biggest preserved collection of ethnographic sources from the German language regions of the former Czechoslovak Republic. The collection contains scores of folk songs, texts of legends, theatrical plays, the ritual folklore, notes on various dialects, local names etc., and also a big set of old photographs and other iconographical material. In present - after the basic archival Processing - the collection contains 76 boxes and is preserved, under the label FNO („Fond německých oblastí“, i. e. Fund of German regions) in the Ethnological Institute of the Academy of Sciences of the Czech Republic. The „Prague collection“ came to being infour timeperiods: 1894-1900, 1906-1918 (the biggest part), 1922-1938, and the last part during the World War II. Until the end of the 1980's it was practically inaccessible, primarily out of the political reasons. Only in the next decade it became the object of Scientific research and simultaneously, because of its damaged state, also object of the work of restoration. After its inventory was made, the subsequent processing, especially the cataloguing of songs, was realized within the framework of the Joint project of the Ethnological Institute of the Academy of Sciences of the Czech Republic and the Deutsches Volksarchiv in Freiburg im Freisgau. The project was financed by the foundation of the Volkswagen company. The result of the project was the preservation of the collection, restoration of the sources, the making of an inventory with the index of localities of origin and the names of collectors, making of copies of the sources and analysis of ali the scores. Precisely to the scores is dedicated the second part of the present article. In its final part the author outlines the fields of study that can use this collection as a unique source base. Even though the Scientific analysis o f the „Prague collection“ has not been completed yet and the majority of the sources waits for publication, it is obvious its extraordinary cultural value and cultural-political importance.
The paper presents and analyses the Talbot effect - self-imaging of a periodical structure in given distances behind a template, if the template is illuminated by a plane wave. This phenomenon has many applicationsin optical metrology and in industry. The detailed mathematical analysis with an amplitude grating illuminated by a monochromatic plane and spherical wave is performed. Afterwards, the applications in optical metrology, lithography, and measuring displacements are shown and described. and V práci je představen a analyzován Talbotův jev - samozobrazování periodické struktury v určitých vzdálenostech za svou předlohou, je-li tato předloha osvětlena rovinnou vlnou. Tento jev má řadu praktických aplikací v optické metrologii a průmyslu. Je provedena podrobná matematická analýza na příkladu amplitudové mřížky osvětlené monochromatickou rovinnou a sférickou vlnou, a dále jsou představeny a popsány vybrané aplikace využívající tento jev v oblasti optické metrologie, litografie a měření posunů.