22£ Scientific Intelligence — Meteorology. 



distance from the eagle and the dolphin ; passing 6 of the Eagle, 

 it was suddenly extinguished near a Capricorn, a little to the east 

 of that star, leaving behind it a long luminous train. The du- 

 ration was not above 6" or 7"; nevertheless, as the light which it 

 diffused made me turn my eyes to the quarter from which it came, 

 it is probable that the meteor had existed for some seconds before 

 I perceived it. lis form was rounded at the lower part (that 

 which, following the movement of the ball, was in front) ; the 

 upper^part was less distinctly terminated. It gave out in all 

 directions brilliant rays of white light. Its diameter, in a hori- 

 zontal direction, seemed to me equal to a fourth part of that of 

 the moon. The sudden appearance of a light so vivid, in a sky 

 which was quite obscure (the moon had not then risen), called 

 forth an^exclamation of surprize from all those near me who were 

 witnesses of the phenomenon." 



8. Aurora Borealis. — In terminating a communication made 

 to the Petersburgh Academy, regarding the aurora of the 18th 

 October 1836, as seen at Dorpat, MM. Struve and W. Preuss 

 deduce the following general conclusions : — " The greyish seg- 

 ment placed near the northern point of the horizon, which seemed 

 to serve as the base of the whole aurora, and which we perceived 

 for a long time at Dorpat, is only the darkened colour of the 

 sky and not a cloud. We have often observed this segment in 

 very obscure nights and at considerable heights above the hori- 

 zon, and we have then constantly seen the stars without any 

 sensible diminution of their light. Its obscurity is only the con- 

 sequence of the contrast which exists between it and the lumi- 

 nous arches which surround it. When the segment is in part di- 

 vided and illuminated by the luminous arches, we must attribute 

 this effect to the existence of the luminous matter in the parts of 

 the sky which did not previously exhibit any brightness. 2. It 

 appears to us very probable that the distance of the aurora from 

 the observer is not very considerable, at least when the aurora 

 is vividly extendt.d and intense ; and that the position of the 

 light is in the clouds. We may even conjecture that the phe- 

 nomenon of the polar light is partly to be attributed to the con- 

 stitution of the atmosphere in the region of the clouds. The 

 i-eflection of the aurora on the whole surface of the ascensional 

 cloud, is explained by the short distance between the earth and 



