86 On the Height of the Aurora Borealis. 



bright, yet, they do not seem to have been seen by any other 

 observer, as farther on he says, " I have thought fit to annex 

 a figure exhibiting the particular appearance of the two 

 laminae vi'hich I saw at London, between 10 and 11 ; more 

 especially, because I do not find, among the many relations I 

 have seen, any one that has taken notice of it." 



From these extracts, I think it may be fairly inferred, that 

 on this occasion, (as also during the late aurora), although 

 auroral action was going on simultaneously over a great space, 

 and presented generally similar appearances, yet the same 

 appearances were not in reality seen at different places ; and 

 thus one of the great arguments in support of the opinions 

 which ascribe such great elevation to the aurora, is removed. 



This extraordinary aurora was seen over all the north of 

 Europe, from the west of Ireland to the confines of Russia 

 and Poland on the east ; as also on the north-west coast of 

 Spain. From this it has been considered that its elevation 

 must have been exceeding great, but I cannot think it proves 

 more than that the auroral action was going on simulta- 

 neously over these countries. 



And in fact, there is strong evidence to tlie contrary, as in 

 another article on the subject, (p. 430), there is the following 

 passage : " In our last, we endeavoured to give the public 

 as good an account of the late surprising meteors seen in the 

 heavens on the 6th of March last, as could be gathered from 

 the several relations of very distant spectators, which had 

 come to the Hoyal Society's notice ; and since then, we can 

 only add thereto, that at Paris, the light was so inconsider- 

 able, that it was not regarded.'' 



This fact, that the auroral light was not seen at Paris, 

 tells strongly against the theory of the great elevation of the 

 aurora. But to this evidence, it may be objected that clouds 

 may have prevented the light being seen at Paris. If this 

 had been the case, it surely would have been noticed by 

 Halley, as the subject excited so much interest at the time 

 as to produce a special report at the request of the Eoyal 

 Society, 



There is another instance of an aurora mentioned by Dr 

 Halley, which may also be advanced, i. e., " That of the year 



