For this purpose he examined numerous libraries and archives, and published (1727–1729) histories of the Church of Lorch and of the Sees of Passau and Salzburg: Germaniae Sacrae tomus primus: Metropolis Laureacensis cum episcopatu Pataviensi chronologice proposita (Augsburg, 1727), and an Archiepiscopatus Salisburgensis chronologice propositus (Vienna, 1729).
However, the only result of his industry published by him on these subjects was a preliminary inquiry into the earliest periods of the See of Ratisbon, Germaniae sacrae tomus tortius.
Contrary to the Salzburg tradition, he maintained in his second volume that this see was founded by St. Rupert at the close of the seventh century; this aroused opposition.
With advancing age he ceased personal researches, but induced his younger Jesuit peers, in Graz and Klagenfurt, to take up and carry on his work.
With the same end in view he communicated, only a short time before his death, with the learned prince abbot, Martin Gerbert, the result being that the Benedictine priests, Emil Usserman, Ambrosius Eichhorn, and Trudpert Neugart, took charge of the work for the Dioceses of Würzburg, Chur, and Constanz.