52 



ON THE PERIODICITY OF THE AURORA BOREALIS. 



Stuttgart. Volzius. 



Stuttgart. Volzius. 



Vpsal. Ferner. 



Vpsal. Ferner. 



Upsal. Ferner. 



Stuttgart. Volzius. 



Near Philadelphia. Kalm. 



Cambridge. Wintlirop. Lovering. 



Upsal. Ferner. 1 



Stuttgart. Volzius. 



Cambridge. "Wintlirop. Lovering. 



Upsal. Ferner. 



Upsal. Ferner. 



Upsal. Ferner. Wargentin.- 



Upsal. Ferner. 



Upsal. Ferner. 



Upsal. Ferner. 



Upsal. Ferner. 



Upsal. Ferner. Stuttgart. Volzius. 



Steinebrunn. Bischoff. 



Upsal. Ferner. 



Upsal. Ferner. 



Stuttgart. Volzius. 



Stuttgart. Volzius. 



Stuttgart. Volzius. 



Stuttgart. Volzius. 



I psal. Ferner. 



Cambridge. Winthrop. Lovering. 



Upsal. Ferner. 



Gottingen. Hollmann. 



Stuttgart. Volzius. 



Gottingen. Hollmann. 



Upsal. "Wargentin. 



Upsal. Ferner. Stuttgart. Volzius. 



Cambridge. Winthrop. Lovering. 



Stuttgart. Volzius. 



Stuttgart. Volzius. 



Stuttgart. Volzius. 



Gottingen. Hollmann. 



Cambridge. Winthrop. Lovering. 



Stuttgart. Volzius. 



Cambridge. Winthrop. Lovering. 



Canada. Kalm. 



Upsal. Ferner. 



Upsal. Ferner. 



Upsal. Ferner. 



Upsal. Ferner. 



1 Svenska Vetensk. Acad. XIII. 215. 



2 Acad. Coil. Etrang. Dijon. XI. 191. 

 Acad. XI. 57. 



Svenska Vetensk. 



Sept.13. 



Cambridge. Winthrop. Lovering. 



Italy. Beccari. Mairan. 



Italy. Beccari. Mairan. 



Leipsic. Heinsio. 1 Gottingen. Hollmann. 



Tubingen. Kraft. Steinebrunn. Bischoff. 



Upsal. Ferner. Italy. Beccari. Mairan. 



Upsal. Ferner. 



I psal. Ferner. 



Cambridge. Winthrop. Lovering. 



Upsal. Ferner. 



Ipsa!. Ferner. 



Cambridge. Winthrop. Lovering. 



I 'jisal. Ferner. 



Cambridge. Winthrop. Lovering. 



Upsal. Ferner. 



Upsal. Ferner. 



Upsal. Ferner. 



Upsal. Ferner. 



1750. 



Upsal. Ferner. 



/ 'psal. Ferner. 



Cambridge. Winthrop. Lovering. 



Cambridge. Winthrop. Lovering. 



Wittemberg. AVeidler. Mairan. 



Tooting. Miles. Baker. 2 Reuss. 



Leipsic. Heinsio. Upsal. Ferner. 8 



Italy. Beccari. Mairan. 



Wittemberg. Weidler. Thompson. 



Chelsea. Martyn. 4 Paris. Fouchi. 6 



Cambridge. Winthrop. Lovering. 



Wittemberg. Weidler. Mairan. 



Gottingen. Hollman. 



Italy. Beccari. Mairan. 



Upsal. Ferner. 



Upsal. Ferner. Gottingen. Hollmann. 



Tubingen. Kraft. 6 Steinebrunn. Bischoff. 



Upsal. Ferner. Plymouth. Huxham. 



Mairan, Reuss, and Phil. Trans. 



I psal. Ferner. Thompson. 



Cambridge. Winthrop. Lovering. 



Wittemberg. Weidler. Mairan. Reuss. 



i N. Comm. Petrop. IV. 477. 



2 Phil. Trans. XLVI. 346 & 399, where it is accidentally put 

 down for Jan. 23, 1751, though the communication bears an 

 earlier date. 



8 Svenska Vetensk. Acad. XIV. 255. 



* Phil. Trans. XLVI. 319. 



6 Encyc. Method. I. 353. 



6 N. Comm. Petrop. V. 403. 



