70 



November 2nd. Professor Phillips in the Chair. 



" On the Aurora Borealis of October 24<t/i, 1847 ;* as seen 

 at Yorhy — By Prof. John Phillips, P. R. S., &c. 



The Author, having explained the general characters of 

 Auroral exhibitions as they appear in the latitude of York, and 

 directed attention to the periods of their occurrence, (annual 

 and hourly,) the peculiarities of their light (in form, distri- 

 bution, and colour), their relation in space to lines of magnetic 

 sjTumetry, (axal and equatorial), and the local disturbance 

 which they occasion in the momentary position of these mag- 

 netic lines, enumerated the main features of the luminous 

 meteor of October 24th, as follows : 



1. "In form this Aurora was composed of narrow beams 

 and irregular expansions of light. When most complete, be- 

 tween 9'30 and 10*30 (York time) the whole of the northern 

 zone from horizon to zenith, and a large segment of the sky 

 south of the zenith, but not reaching to the horizon, were 

 covered by innumerable beams finely pencilled in white light, 

 and extending from all sides upwards till they reached a 

 point S. S. E. of the zenith, and formed there a crowTi of many 

 rays and great brightness. At irregular intervals the light was 

 withdrawn from the beams, and again flashed out in new forms ; 

 and if the beams Avere compared to the lines of longitude on a 

 globe, they were often interrupted by continuous band-like zones 

 of latitude concentric with the pole of the beams, through 

 which the clear sky was visible. Round the pole also was fre- 

 quently seen a nearly circular space clear from beams, 



2. Irregular expansions of light appeared in two parts of the 

 sky, viz., in the magnetically East and West parts, and there, 

 expansions large and red as the smoke masses over Y'ork Min- 

 ster when it was on fire, were crossed by white narrow beams 

 in great numbers. Several times red beams rose 60<* in height 

 from the magnetic East, and both on the East and West mag- 

 netic lines, but no where else, red fl.ashe8 passed occasionally to 

 the centre of the crown. 



(Proceedings Y. P. S., 1847.) 



