Unknown, :  54 lectures

  Landin, Germany:   2 lectures

  Aarau, Switzerland:   1 lecture

  Leipzig, Germany:  92 lectures

  Amsterdam, Netherlands:   8 lectures

  Liestal, Switzerland:   2 lectures

  Arlesheim, Switzerland:   2 lectures

  Linz, Austria:   4 lectures

  Arnhem, Netherlands:   7 lectures

  Locarno, Switzerland:   1 lecture

  Augsburg, Germany:   2 lectures

  London, England:  29 lectures

  Barr, Alsace-Lorraine:   1 lecture

  Lugano, Switzerland:   2 lectures

  Basel, Switzerland: 132 lectures

  Mainz, Germany:   1 lecture

  Bergen, Norway:   3 lectures

  Malsch, Germany:   2 lectures

  Berlin, Germany: 960 lectures

  Mannheim, Germany:  11 lectures

  Bern, Switzerland:  58 lectures

  Milan, Italy:   3 lectures

  Bielefeld, Germany:   3 lectures

  Munich, Germany: 239 lectures

  Bingley, England:   1 lecture

  Neuchatel, Switzerland:   3 lectures

  Bochum, Germany:   1 lecture

  Nijmegen, Netherlands:   2 lectures

  Bologna, Italy:   4 lectures

  No city, No where:   6 lectures

  Bonn, Germany:   4 lectures

  Norrkoeping, Sweden:  10 lectures

  Bottmingen, Germany:   9 lectures

  Nuremberg, Germany:  44 lectures

  Bremen, Germany:  18 lectures

  Olten, Switzerland:   2 lectures

  Breslau, Poland:  18 lectures

  Oosterbeek, Netherlands:  11 lectures

  Budapest, Hungary:  12 lectures

  Oslo, Norway:  78 lectures

  Cassel, Germany:  59 lectures

  Oxford, England:  18 lectures

  Colmar, France:   1 lecture

  Palermo, Italy:   1 lecture

  Cologne, Germany:  77 lectures

  Paris, France:  30 lectures

  Copenhagen, Denmark:  15 lectures

  Penmaenmawr, Wales:  23 lectures

  Darmstadt, Germany:   8 lectures

  Pforzheim, Germany:   5 lectures

  Delft, Netherlands:   2 lectures

  Prague, Czechoslovakia:  32 lectures

  Dornach, Switzerland:1700 lectures

  Regensburg, Germany:   1 lecture

  Dresden, Germany:   7 lectures

  Reinach, Switzerland:   1 lecture

  Dusseldorf, Germany:  46 lectures

  Rome, Italy:  11 lectures

  Eisenach, Germany:   1 lecture

  Rotterdam, Netherlands:   2 lectures

  Elberfeld, Germany:   9 lectures

  Solothurn, Switzerland:   1 lecture

  Erfurt, Germany:   1 lecture

  Spandau, Germany:   1 lecture

  Essen, Germany:   2 lectures

  St. Gallen, Switzerland:   9 lectures

  Frankfurt, Germany:   7 lectures

  Stockholm, Sweden:  20 lectures

  Freiburg, Germany:   3 lectures

  Strassburg, France:   7 lectures

  Graz, Austria:   1 lecture

  Stratford-on-Avon, England:   2 lectures

  Hamburg, Germany:  67 lectures

  Stuttgart, Germany: 623 lectures

  Hannover, Germany:  53 lectures

  Tannbach, Austria:   1 lecture

  Hedelfingen, Germany:   1 lecture

  Tegel, Germany:   1 lecture

  Heidelberg, Germany:   9 lectures

  The Hague, Netherlands:  55 lectures

  Heidenheim, Germany:   3 lectures

  Torquay, England:  24 lectures

  Helsinki, Finland:  24 lectures

  Tubingen, Germany:   4 lectures

  Hermannstadt, Romania:   1 lecture

  Ulm, Germany:   5 lectures

  Hilversum, Netherlands:   3 lectures

  Utrecht, Netherlands:   2 lectures

  Ilkley, England:  19 lectures

  Vienna, Austria:  72 lectures

  Karlsruhe, Germany:  19 lectures

  Weimar, Germany:  17 lectures

  Klagenfurt, Austria:   1 lecture

  Wiesbaden, Germany:   4 lectures

  Koberwitz, Poland:  14 lectures

  Winterthur, Switzerland:   5 lectures

  Koblenz, Germany:   1 lecture

  Zurich, Switzerland:  57 lectures