1823.] Proceedings of Philosophical Societies. 391 



The lower extremities quiver with a fiery red colour, and the 

 upper with orange. We once saw violet in the former. The 

 number of Auroras visible in September was two ; in October, 

 three ; in November, three ; in December, five ; in January, 

 five ; in February, seven ; in March, sixteen ; in April, fifteen ; 

 and in May, eleven. Calm and clear weather was the most 

 favourable for observation ; but it is discernible in cloudy wea- 

 ther, and through mists. We could not perceive that it affected 

 the weather. The magnetic needle, in the open air, was disturbed 

 by the Aurora, whenever it approached the zenith. Its motion 

 was not vibratory, as observed by Mr. Dalton ; and this was, 

 perhaps, owing to the weight of the card attached to it. It 

 moved slowly to the £ or W of the magnetic meridian, and 

 seldom recovered its original direction in less than eight or nine 

 hours. The greatest extent of its aberration was 45V 



"A delicate electrometer, suspended at the height of fifty feet 

 from the ground, was never perceptibly affected by the Aurora, 

 nor could we distinguish its rustling noise, of which, however, 

 such strong testimony has been given to us, that no doubt can 

 remain of the fact. The conclusions to be drawn from the 

 above will be found in the observations for the winter of 1820." 



(To be continued.) 



Article XV. 



Proceedings of Philosophical Societies. 



ROYAL SOCIETY. 



* # * We endeavoured, last month, to give a full report of the 

 important paper communicated by the President to the Royal 

 Society, on the 5th of March ; but writing only from memory, 

 we have made two errors, one with respect to the rotation of the 

 mercury not being stopped, but produced, by the approximation 

 of the magnet ; the other in the historical paragraph in the con- 

 clusion, which, as we have stated it, is unjust to Mr. Faraday, 

 and does not at all convey the sense of the author. We wish, 

 therefore, to refer our readers forward to the original paper, when 

 it shall be publish ed, for the correction of these mistakes.— Edit. 



March 20.— At this meeting the reading of the following 

 paper, which had been commenced on the 13th, was resumed 

 and concluded. . 



Of the Motions, of the Eye, in Illustration of the Uses of the 

 Muscles of the Orbit, By Charles Cell, Esq. (Communicated 

 by the President.) 



