1. Editorial statement

   • Henk J. M. Bos
   • Jed Z. Buchwald

   EditorialNotes Pages: 1 - 1

2. On the origins of Dénes König's infinity lemma

   • Miriam Franchella

   OriginalPaper Pages: 3 - 27

3. Hidden lemmas in Euler's summation of the reciprocals of the squares

   • Mark McKinzie
   • Curtis Tuckey

   OriginalPaper Pages: 29 - 57

4. A note on ‘Kepler's equation’

   • Jacques Dutka

   OriginalPaper Pages: 59 - 65

5. Becquerel and the choice of uranium compounds

   • Roberto de Andrade Martins

   OriginalPaper Pages: 67 - 81