114 



ON THE SECULAR PERIODICITY OF THE AURORA BOREALIS. 



* 



141 Oct. 25 



142 

 143 



u 



u 



Evening. 

 Evening. 



Small Aurora Borealis. 

 Small Aurora Borealis. 



26. 



27. Evening. Aurora Borealis. 



144 Dec. 6. Evening. Aurora Borealis. 



146 



152 

 153 

 154 

 155 



156 



158 



161 



163 



164 



165 



167 



169 



171 

 172 



1770. 



145 Jan. 17 



Evening. 



" 18. Evening. 



East. 



Aurora Borealis. 

 Aurora radiating in 



the 



147 Feb. 28. Evening, Aurora Borealis. 



148 Mar. 23. 



Evening. 



Aurora Borealis, and a glo- 



rious arch from East to West. 



149 April 19. 



150 May 16. 



Evening. 

 Evening. 



Great Aurora Borealis. 

 Small Aurora Borealis. 



151 July 14. Evening. Aurora Borealis 



u 



u 



u 



16. 



27. 



Evening. 

 Evening. 



Aurora Borealis. 

 Small Aurora Borealis 



31. Evening. Aurora Borealis. 



Aug. 27. 



Evening. 



Bright Aurora Borealis 



4< 



31. Evening. Aurora Borealis. 



157 Sept 9. 



u 



10. 



Evening, 

 Evening 



Aurora Borealis. 

 Aurora Borealis. 



1771. 



159 Feb. 19. (10£ h , P. M.) Aurora Borealis. 



160 Mar. 17. Evening. Very 



bright 



Aurora Bo- 



« 18. 



162 June 2. 



realis. 

 Evening. 

 Evening. 



Small Aurora Borealis. 

 Bright Aurora Borealis be- 



hind the clouds. 



.. 



Aug. 



12. 



16. 



17. 



166 Sept. 13. 



Evening. 

 Evening. 



Evening. 



Evening. 



Little Aurora Borealis. 

 Small Aurora Borealis. 

 Small Aurora Borealis. 

 Small Aurora Borealis. 



u 



17. Evening. Aurora Borealis. 



168 Oct. 4. 



« 



18. 



170 Nov. 1. 



Evening. 



Evening. 

 Evening. 



Small Aurora. 

 Aurora Borealis. 

 Aurora Borealis. 



44 



44 



5. Evening. Aurora Borealis. 



12. 



Evening. 



Small Aurora Borealis 



173 Dec. 4. Evening. Little Aurora Borealis. 



1772. 



174 Feb. 27. Evening. Aurora Borealis. 



175 April 12. (10 h ,P.M,) Small Aurora Borealis. 



(4 



ii 



7. 



176 July 5. 

 177 



178 



179 



Evening. 

 Evening. 



Aurora Borealis. 

 Aurora Borealis. 



8. Evening. Great Aurora Borealis. 



25. 



Evening, 

 alis. 



Remarkable Aurora Bore- 



180 Oct. 2. Evening. Aurora Borealis. 



182 



184 



187 

 188 

 189 

 190 



209 



211 



214 



220 



1773. 



181 Jan. 17. 



a 



19. 



Evening. 

 Evening. 



Great Aurora Borealis. 



Great 



streaming 



Aurora 



Borealis. 



183 Mar. 15 



E 



u 



23 



185 May 19 



186 June 6 



venmg 



Evening. 



Evening. 

 Evening. 



Aurora Borealis. 

 Aurora Borealis. 

 Aurora Borealis. 

 Aurora Borealis. 



" 10. Evening. Small Aurora Borealis 



u 



it 



<( 



13. 

 14. 

 24. 



191 July 12. 



192 " 17. 

 193 



Evening. 

 Evening. 

 Evening. 

 Evening. 

 Evening. 



Small Aurora Borealis. 

 Small Aurora Borealis. 

 Aurora Borealis. 

 Uncommon Aurora Borealis. 

 Great Aurora Borealis. 



" 18. Evening. Small Aurora Borealis. 



194 . " 25. Evening. Aurora Borealis. 



195 Aug. 15. Evening. Aurora Borealis. 

 196 



Aug. 15 

 " 25 



Evening. 



Aurora Borealis in North- 



west. 



1774. 



197 Feb. 28. 



198 Mar. 13. 



199 April 3. 



Evening. 

 Evening. 

 Evening. 



Aurora Borealis. 

 Great Aurora Borealis 

 Aurora Borealis. 



200 June 4. Evening. Little Aurora Borealis 



201 July 9. Evening. Aurora Borealis. 



a 



a 



a 



« 



12. 



13. 



28. 

 29. 



Aug. 14 



26, 



Aurora Borealis. 

 Small Aurora Borealis. 

 Little Aurora Borealis. 

 Little Aurora Borealis. 

 Evening. Great Aurora Borealis. 



202 

 203 

 204 

 205 



206 



207 * 26. Evening. Aurora Borealis. 



208 Sept. 1. Evening. Aurora Borealis. 



Aurora Borealis. 



Evening. 

 Evening. 

 Evening. 

 Evening. 



a 



10 



Evening. 



210 Nov. 3. Evening. Aurora Borealis. 



Aurora Borealis. 



5 



Evening. 



1775. 



212 Jan. 29 



213 Feb. 2 



Evening. 



Aurora Borealis. 



(ll£ h ,P.M.) Little Aurora Borealis 



u 



21 



Evening. 



Aurora Borealis. 



215 Mar. 25 



(I0| h , P. M.) Small Aurora BoreaUs. 



216 July 18. Evening. Aurora Borealis 



1776. 



217 April 18 



218 Sept. 4 

 219 



Evening. 

 Evening. 



Aurora Borealis 

 Aurora Borealis 



a 



« 



5. Evening. Aurora Borealis 



Aurora Borealis 



16 



Evening. 



1777. 



221 Jan. 28. Evening. Aurora Borealis 



