Proceedings of Learned Societies. 305 



60. ^ Gygni. 3"*5. 184 0, 2. 5-| and 8. Bright white and 

 lilac. 



OCCULTATIOJSTS. 



There will be three occultations at convenient honrs during 

 the present month. The earliest will be a fine one, well worth 

 looking for. Nov. 6. S Arietis, 4| mag., will disappear (at 

 Greenwich) at lOh. 6m., and reappear at llh. 22m. 24th, a 

 6 mag. star, No. 6539 B. A. C. (i. e. of the British Association 

 Catalogue) will be covered by the moon's limb at 6h. 31m., 

 and come forth at 7h. 4m. 30th, 45 Piscimn, 6 mag., will be 

 occulted from 7h. 21m. till 8h. 22m. 



PROCEEDINGS OF LEARNED SOCIETIES. 



BY W. B. TEGETMEIER. 



BRITISH ASSOCIATION FOR THE ADVANCEMENT OF 



SCIENCE. 



The Thirty-second Annual Meeting of the British Association 

 was held this season at Cambridge, under the presidency of Pro- 

 fessor Willis, who delivered the inaugural address, which was chiefly 

 devoted to the details of the Society's expenditure. In the lecture 

 devoted to Intellectual and Physical Science, Mr. J. Nasmyth de- 

 scribed " The Features of the Sun's Surface," as at present 

 known. The spots he regarded as gaps or holes in the luminous 

 surface of the sun, exposing the dark nucleus, and over this appears 

 a thin, gauze-like veil, then comes the penumbral stratum, and over 

 all the luminous stratum, which he had discovered to consist of 

 lenticular or willow-leaf shaped masses, crossing each other in every 

 direction, so as to hide the dark nucleus, except at the spots. These 

 objects were found to be in constant motion, shooting over the 

 whole surface. Some of them were as large as the surface of the 

 whole earth. 



The Rev. Dr. Pritchard regarded the discovery as one of very 

 high importance in the knowledge of the physical constitution of 

 the sun. 



In connection with this subject, Professor Selwyn showed 

 several " autographs of the sun," taken with his '■ heliautograph," 

 which consists of a camera and instantaneous slide, attached to a 

 refractor of 2f inches aperture, the principle being the same as that 

 of the " photoheiiograph " made for the Kew Observatory. Two of 

 the autographs taken have the edge of the sun in the centre of the 

 photographic plate, showing that the diminution of light towards 

 the edges of the disc is a real phenomenon, and not wholly due to 



