The Gradual of St. Katharinenthal. Codex LM 26117 of the Swiss State Museum Zurich and the Swiss Federal Gottfried Keller Foundation, Canton Thurgau. Facsimile and commentary. Two volumes. 47 x 33,5 cm. Grey brown OKalbs leather over heavy wooden covers with 10 metal fittings with humps and 2 metal clasps on wide leather strands or Ohalf leather. ==References====External links== The Graduale of St. Katharinenthal, created around 1312, is one of the most important Gothic works of art in Switzerland and of great value for the art and cultural history of the beginning of the late Middle Ages.