Mr. Rigaud on Harriots Papers. 271 



too eagerly raised expectations which did not admit of being 

 fulfilled. 



By the kindness of the Earl of Egremont I have recently 

 been entrusted with these very papers ; some of them are very 

 curious, but, as far as I have had time to examine their contents, 

 I have found very little which it would be useful to publish. I 

 can, however, refer you in this respect to better authority 

 than my own. In 1822, Dr. Robertson communicated his 

 reports on them to Dr. Brewster, and they were printed in the 

 Edinburgh Philosophical Journal (vol. vi. p. 314). They refer, 

 of course, only to those papers which were sent to Oxford ; of 

 the remainder any one in London may form his own opinion, 

 as a considerable quantity of them was given^ I believe, in 

 1810, by Lord Egremont, to the British Museum. There were, 

 before that time, some other MSS. of Harriot's in the same 

 place (No. 6001-2, and 6083 of the Harleian collection) ; An- 

 tony Wood (Ath. Ox. vol. i. p. 391, 1st. ed.) speaks of a MS. 

 of his, entitled e Ephemiris Chyrometrica,' which he says was 

 in the library of Sion College, but no mention of it is to be 

 found in Reading's Catalogue ; and, although Harriot was an 

 Oxford man, I am not at present aware of our having any 

 papers of his in any of our libraries. 



S. P. RIGAUD. 



ON THE MAGNETIC INFLUENCE EXHIBITED DURING 



AN AURORA BOREALIS. 

 By S. H. CHRISTIE, Esq. M.A. F.R.S. &c. 



TN an account which I gave of some observations on the 

 aurora borealis of the 7th of January last, I stated that it 

 was my intention to adjust a magnetic needle for the purpose 

 of observing the effects produced on it during an aurora, should 

 there be any recurrence of the phenomenon. This I immedi- 

 ately did, but was not fortunate enough to be able to make any 

 observations until the aurora of the 19th of April. 



In order that the nature of the action on the needle may be 

 clearly understood, it is necessary that I should point out the 



