Nor did Hermann write the _Sancti Spiritus adsit_; for this, on the best of testimony, was Notker’s. It was so sung at Rome under Innocent III.; and Ekkehard the Younger, in his history of Notker, pointedly claims it for him. It is very doubtful whether Hermann invented the astrolabe for measuring the distances of stars. His two treatises are upon its use, and he is evidently very familiar with it. But it was first made serviceable in navigation by the Portuguese—if we are to believe Evelyn (in his _Navigation_)—and the study of astronomy was greatly cultivated by the Arabic schools in Spain and elsewhere about this period. J. A. Fabricius indeed mentions that the astrolabe was “commonly employed in the days of Ptolemy.” The _Ave Maria_ is supposed by Koch to belong to the thirteenth century and some have ascribed it to Adam of St. Victor. It is, perhaps, by Heribert of Eichstettin (died 1042). Hermann wrote the _Ave praeclara maris stella_, which might have been mistaken for this other. The _Salve regina_ is assigned by Durand to Peter of Compostella. Gerbert names several possible authors, but evidently follows the leadership of Durand. (_De Cantu, etc._, II., 27.) And yet Trithemius, with every really critical scholar, credits it to Hermann. It is exhaustively considered by Wegelin and definitely conceded to him. (_Thes. Rerum Suevicarum_, II., p. 120 _ff._) Robert the Second cannot claim the _Chorus novae Hierusalem_. It is the production of Fulbert of Chartres (died 1029), and is included without question in every complete edition of his works. Thus the absolute authority of Durand is much shaken. He was a lawyer in the thirteenth century, who studied at Bologna and taught at Modena; a legate of Pope Martin IV.; dean of the church at Chartres, and Bishop of Mende. The fact that he was dean of Chartres, and yet ascribes the _Chorus Novae_, not to Fulbert but to Hermannus, is suggestive, but not convincing.