Bonjour à tous ,et merci Varese.
Reading myself

,I remember there was a Farman tandem triplane ,never finished ,built in 1908 :The Farman Flying Fish.
I think that it is the origin of Jane's error .
Remains now the story of the Fritzsche tandem before and after its designer death ...
It seems that Lange+Hackenberger could be right ....