ON THE PERIODICITY OF THE AURORA BOREALIS. 



79 



Rochelle. Seignette. 



Spydberg. Wilse. 



St. Petersburg. Euler. Laon. Cotte. 1 



Berlin. Beguelin. Erfurt. Planer. 



Sagan. Preus. Brussels. Mann. 



Mannheim. Koenig. Brussels. Mann. 



Sagan '? Preus. Laon. Cotte. 



Stockholm. Nicander. 



Cambridge. Wigglesworth. Lovering. 



New Haven. Stiles. Loomis. 



Mannheim. Koenig. Stockholm. Nicander. 



Berlin. Beguelin. Sagan ? Preus. 



Cambridge. Wigglesworth. Lovering. 



Stockholm. Nicander. 



Mannheim. Hemmer. 



Cambridge. Wigglesworth. Lovering. 



Berlin. Beguelin. 



Spydberg. Wilse. 



Spydberg. Wilse. 



Spydberg. Wilse. 



Stockholm. Nicander. 



Copenhagen. Bugge. 



1786. 



Prague. Strnad. Sagan ? Preus. 

 Mannheim. Hemmer, 

 Brussels. Mann. 



Lowenorn. 2 



Tigurina Aedes. Gothard. 



St. Petersburg. Euler. 8 



Stockholm. Nicander. Spydberg. Wilse. 



Cambridge. Williams. 



Salem. Holyoke. Lovering. 



Stockholm. Nicander. 



Berlin. Beguelin. Sagan ? Preus. 



Spydberg. Wilse. 



Berlin. Beguelin. 



Stockholm. Nicander. 



St. Petersburg. Euler. 



Cambridge. Wigglesworth. Lovering. 



Cambridge. Williams. 



Salem. Holyoke. Lovering. Spydberg. Wilse. 



New Haven. Stiles. Loomis. 



Berlin. Beguelin. Copenhagen. Bugge. 



St. Petersburg. Euler. Brussels. Mann. 4 



St. Petersburg. Euler. 



1 Journ. des Savans, 1786, p. 112. 



2 Thompson's Met. p. 349. 



8 Acta Soc. Acad. Petrop. 1786. Pt. II. p. 321. 

 4 Mem. de l'Acad. Brux. V. 445. 



St. Petersburg. Euler. 



Stockholm. Nicander. Spydberg. Wilse. 



St. Petersburg. Euler. 



Stockholm. Nicander. Spydberg. Wilse. 



St. Petersburg. Euler. 



Stockholm. Nicander. 



St. Petersburg. Euler. 



Cambridge. . Wigglesworth. Lovering. 



Cambridge. Williams. 



New Haven. Stiles. Loomis. 



St. Petersburg. Euler. 



Stockholm. Nicander. 



<Sif. Petersburg. Euler. 



Stockholm. Nicander. Spydberg. Wilse. 



Cambridge. Wigglesworth. Lovering. 



Cambridge. Williams. 



Salem. Holyoke. Lovering. 



New Haven. Stiles. Loomis. 



Moscow. Stritter. Paris. Cassini. 1 



St. Petersburg. Euler. Prague. Strnad. 



Stockholm. Nicander. Spydberg. Wilse. 



New Haven. Stiles. Loomis. 



Erfurt. Planer. Moscow. Stritter. 



St. Petersburg. Euler. Berlin. Beguelin. 



Salem. Holyoke. Lovering. 



New Haven. Stiles. Loomis. Sagan ? Preus. 



Cambridge. Wigglesworth. Lovering. 



Cambridge. Williams. 



New Haven. Stiles. Loomis. Sutz. Spriingli. 



Brussels. Mann. Ratisbon. Heinrich. 



Marseilles. St. Jacques. Padua. Toaldo. 



Peissenberg. Schwaiger. Berne. Studer. 



Prague. Strnad. Sagan ? Preus. 



New Haven. Stiles. Loomis. 



Mount St. Andex. Kettel. Buda. Bruna. 



Munich. Huebpauer. Sagan ? Preus. 



Rome. Calandrelli. Stockholm. Nicander. 



Cambridge. Wigglesworth. Lovering. 



Salem. Holyoke. Lovering. 



Berlin. Beguelin. Mannheim. Hemmer. 



Marseilles. St. Jacques. 



Cambridge. Wigglesworth. Lovering. 



G mbridge. Williams. 



Salem. Holyoke. Lovering. 



New Haven. Stiles. Loomis. 



Mannheim. Hemmer. 



St. Petersburg. Euler. Moscow. Stritter. 



Marseilles. St. Jacques. Sagan ? Preus. 



1 Mem. de l'Acad. 1786. 



