I'm reading the diary of Andreas Ly a Chinese catholic priest serving in Sichuan in the 18th c. and had trouble with the use of quatenus in the following sentence
Diarium, p.2 wrote:Dum lunâ octavâ anni 1746, ubique locorum rumor persequutionis contra christianos ex mandato Imperatoris excitatae, sparsus esset, Reverendus Dominus Paulus Sou, cujus curae commissa erat ecclesia Hia-sse-hiang ex urbe hâc Tching-tou in qua tunc erat, epislolâ ad Patrem Seifone tunc in dicto pago Hia-sse-hiang degentem missâ, rogavit ut tabulas vulgo pien nuncupatas, tum Reguli, tum Praefectorum, in honorem supradicti Domini Pauli, quatenus mathematici, in sala praedictae ecclesiae appensas, quantocius tolli, et ipsi tradi juberet; res etiam Illustrissimorum Praesulum bonae memoriae Dominorum Mullener et Maggi in ecclesiâ servatas, christianorum ad domos transferri, commendavit.
So, Paul Sou asks for the tablets to be removed as soon as possible and these tablets are described as tum Reguli, tum Praefectorum, in honorem supradicti Domini Pauli, quatenus mathematici,
"both of the viceroy and the Prefects, in honor of the aforementioned priest Paul, quatenus mathematician,...".
It seems to me that here quatenus doesn't introduce a clause and is used as an adverb. It could mean something like "until then mathematician" > "at the time (the tablets were made)" but I can't find any parallel for such a use of quatenus...Or that the tablets were made in his honor "in so far as he is mathematician" but then why the genitive, mathematici ?