AUEORAS OBSERVED AT CAMBRIDGE 



As it was at about the same altitude as the 

 star, viz., 74° 52', and to the east of the merid 

 iau, it could not have been far from the mag- 

 netic pole of Dip. Shortly afterwards, the 

 arch was broken up and the northern sky 

 covered with pulsations of light. 

 *18 May 29. Brilliant Aurora. The auroral arch 

 was first seen at ( J h S m P. M., extending from 

 a point nearly east to within a few degrees of 

 the western horizon. The light was intense. 

 The apes of the arch was situated, at first 20°, 

 and at 9 h lti m about 30°, south of the zenith. 

 After this time the light broke and scattered, 

 flying from east to west. This arch was en- 

 tirely detached from the main body of the 

 Aurora, and resembled a streamer. In the 

 north there was a diffused light, but very 

 bright and swift flashes toward the zenith. At 

 l(.l h .;.", m , a large meteor was seen in the north, 

 20° high, descending towards the northwest. 

 19 June 21. Faint Aurora at 12 h m . 

 *20 " 26. About 9 ' 12 m P. M., an Aurora was 

 seen in the north, of a white diffused light. 

 At, ll h 56 m , the Aurora assumed a dull appear- 

 ance, with dark wane intermixed. At l h 36 m , 

 the Aurora became more active, and some 

 streamers were seen. The magnetometer was 

 slightly affected at this time. 

 July 4. Between 12 h 4 ,n and lL' h 10 m , bright 

 diffused Northern Lights : occasionally, long 

 streamers : wane clouds near the Northern 

 horizon : magnetometer quiet. 

 July 29. At & h 21 m , an auroral arch was 

 formed, about 7° above the horizon, and very 

 motionless. At 9 h 40 m , it began to move toward 

 tin' zenith, and rose to tlje altitude of 30°. At 

 li h 30'", the Aurora had disappeared. The 

 light was dull during the whole time. 

 *23 Aug. 19. A steady auroral arch was observed. 

 It was double, and the altitude of its apex at 

 10 h 30 m was 7° or 8°. Its color was dull white. 

 This Aurora continued till 10S 36 m , and at 10 h 

 47'" the Northern Lights bad disappeared. 

 *24 " 28. An auroral arch appeared, running 

 from east to west, of intense brightness 

 diffused, hut without streamers. Its apex was 

 nearly on the meridian, and at 9 h 6 m its alti- 

 tude was about 45°. At 9 h 56 m , streamers shot 

 up, G0° from the horizon : the altitude of its 

 highest part was about 76° 43', as found from 

 its place among the stars. 

 Aug. 31. Aurora, bright arch 4°, at 13 b . 



*21 



*22 



26 



*28 



29 

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32 

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35 

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49 



52 

 *54 



Sept. 21. Strong Aurora with streamers, at 12 h . 



Oct. 22. Between 8 h and 9 h , an Aurora of. a 

 steady blue light was first perceived : it af- 

 terwards grew whiter aud brighter. The alti- 

 tude was 3°, with wane clouds below. At ll 1 ' 

 56 m , the Aurora was low. 



Nov. 30. At 10 h , an Aurora was seen of white 

 diffused light. No regular arch was formed. 

 The magnetometer was quiet. 



1841. 



Jan. 14. Aurora, low wane, at 10 h P. M. 

 " 27. Aurora, low and faint, at 9 h 30 m . 

 Feb. 22 Aurora, masses of white light, chiefly 

 E. of N., at 8 h 20 m ,* extending from eastern hor- 

 izon to zenith and passing to the south. 

 " 23. Aurora low at N. by E. Streamer. 

 Mar. 12. Auroral arch, altitude of apex about 5° 

 direction north by 10° east, steady, at 8 U P. M. 

 " 14. Strong Aurora, wane below, masses of 

 white light, detached above, at 7''. 

 " 15. Dull Aurora with wane. 

 " 16. Pale Aurora, low, clear. 

 " 20. Slight Aurora, with wane at north. 

 " 21. Faint Aurora, with dark wane clouds. 

 April 11. Aurora low, with wane. 



" 14. Strong Aurora, with wane intermixed. 

 " 16. Aurora low, at 2° P. M. 

 " 18. Brilliant Aurora, streamers, 5° to 6°. 

 " 19. Aurora, decided arch with faint 

 streamers, at 9 h m . 

 May 8. Aurora, slight. P. M. 

 July 11. Aurora, faint and low at 9 h P. M. 



" 19. Bright Aurora blended with wane, 

 broken double arch, at 9" 30'" P. M. 

 Sept. }!j. Midnight auroral arch, height about 

 5°, steady. 



" 25. Masses of auroral clouds, at 8 h an 

 arch and streamers in N. N. W. 

 " 26. Bed auroral cloud at N. W. 

 Oct. 14. Aurora at 10 h P. M., low, ill-defined, 

 ane. 



Slight Aurora, at ll h 30 m . 

 19. Aurora. 

 ' 21. Aurora, diffused light, steady, and 

 wane clouds low in North, at 9 U P. M. 

 Nov. 18. At 8 h 20 m , a very beautiful Aurora 

 was seen. The period of greatest bright- 

 ness was 8 h l m . At 8 h 26 m , the Aurora had 

 nearly vanished, leaving only faint traces of 

 columns. At 9" 6 m , there was observed in 

 the north a large bright arch of light, mov- 



