198 MATHEMATICS AND NATURAL PHILOSOPHY. 



another which varies between the 6th and 11th magnitudes in somewhat less than 

 a year. The following notes are extracted from our journals : — 



" 1853, February 19. — It is now brighter than 77 Yirginis. Its color is 

 decidedly deep yellow. 



" March 14. — Less than 77 Virginis. It is now bluish white. 



" March 29. — Little diminution of brightness, but a very decided difference in 

 color and appearance between 77 and the variable. On bringing the former to 

 the centre of the field of view it appears perfectly white. The variable star, on 

 the contrary, has a dull aspect, and most undoubtedly very red flashes at times. 

 I examined it attentively, and had not the least doubt of the red flashes in the 

 variable ; as certainly nothing of the kind was presented by 77 Virginis, which 

 was always of a fine white. 



"April 1. — Same appearance, but the color is of a more lurid red. 



" 1854, February 2. — Light vivid, with flashes of a deep red color. 



" February 27. — Dull red. 



" 1855, March 8. — Fine yellow. 



" April 7. — Of a dull amber color, or pale red. 



2. A star near lambda Geminorum, which varies between the ninth magnitude 

 and invisibility in about 10 months, affords similar phenomena. 



" 1848, March 4. — Ninth magnitude and ruddy. 



" October 30. — Same brightness, but bluish. 



" 1852, January 17. — Bluish : no ruddiness about it. 



" January 18 and 20. — The same. 



"February 10. — Light more intense. It is now decidedly yellow, or deep 

 orange. The color has certainly changed from bluish to yellow since January 18. 



" February 25. — Reddish yellow. 



" September 20. — Very slightly, if at all yellow. 



"October 11 and 25. — There is now the yellowish tinge about its light. 



" November 19. — Dull amber color. 



"December 14. — Color livid: no yellowish tinge." 



The same diversity of color was remarked in 1853 and 1854. 



To generalize, I think I may add that when a variable star presents sneeess- 

 ively the colors blue, yellow, and red, the blue tinge is chiefly perceptible as its 

 light increases ; soon after the maximum is past the yellow becomes marked, 

 while on its decrease the curious ruddy tinge and flashes of red tight are noticed. 

 Many of those stars which continue visible about their minima appear hazy and 

 indistinct, as though some cloudy or nebulous medium intervened. These changes 

 however, require closer observation, and as they can hardly fail to have an impor- 

 tant bearing in connexion with the cause of variable light in stars, I venture to 

 recommend them to the attention of the many amateur astronomers 'who possess 

 instruments adapted for such observations. 



At present the phenomena of variable stars mock all attempts at explanation. 



METEOROLOGICAL PHENOMENON. 



A very curious phenomenon was observed at Gateshead, at 6h. 15m. on Wed- 

 nesday morning, Dec. 19th. A bright pillar of blue light appeared to stand up 

 from the horizon at an altitude of about 30 degs. At that point it assumed a very 

 bright appearance, resembling the bursting of a huge rocket. A stream of 

 sparks and haze ascended to a height of al»<>ut 10 degs. more. The light continued 

 visible for about two seconds, illuminating the whole neighbourhood, and waa 



