In 1919 Friedrich GrÃ 1\/4 tzmacher died and Klengel recommended Feuermann should take his job at the GÃ 1\/4 rzenich Conservatory in Cologne . In 1919 cellist Friedrich Wilhelm Ludwig GrÃ 1\/4 tzmacher ( 1866 â `` 1919 ) , the nephew of Friedrich Wilhelm GrÃ 1\/4 tzmacher , died , and Klengel recommended Feuermann for GrÃ 1\/4 tzmacher 's position at the GÃ 1\/4 rzenich Conservatory in Cologne . Feuermann also became principal cellist of the GÃ 1\/4 rzenich Orchestra , by appointment of its conductor ( who was also the conservatory director ) Hermann Abendroth .