1. The ritual origin of counting

   • A. Seidenberg

   OriginalPaper Pages: 1 - 40

2. Alexander von Humboldt and geomagnetic science

   • Sydney Chapman

   OriginalPaper Pages: 41 - 51

3. The main concepts and ideas of fluid dynamics in their historical development

   • P. F. Neményi

   OriginalPaper Pages: 52 - 86