A. MATHEMATICS AND ASTRONOMY. 31 



of June, he was able to recognize the presence of magnesium 

 round the entire limb that is to say, the chromatosphere 

 was completely invaded by the vapor of this metal ; and, al- 

 though the flames of the chromatosphere were very marked 

 and very brilliant, there was a decided absence of protuber- 

 ances. The more marked and brilliant the flames Avere, the 

 brighter and wider appeared the magnesium lines. Very bril- 

 liant and characteristic flames were observed at 2S8. A bright 

 flicula, as anticipated by Tacchini, was found strictly on the 

 limb of the sun. The granulations were very distinct, and 

 the number of small faculaa was in exact agreement Avith the 

 presence of magnesium. On several occasions the A r ariation 

 of the Avidth of the lines accorded perfectly with the A r aria- 

 tion of the luminous intensity of the chromatospheric flames 

 observed at the place of the line C. 



At the latest dates a great abundance of magnesium still 

 continued, although not around the Avhole limb ; and the ob- 

 servations proved, not that local eruptions took place, but ra- 

 ther complete expulsions that is to say, a mixture of certain 

 metallic vapors with the chromatosphere, extending over the 

 entire surface of the sun, Avhich consequently Avould appear 

 to be still in a gaseous state. 



SeA T eral persons had remarked to Tacchini that the light of 

 the sun did not appear to present its ordinary aspect, and 

 the observations made at the Italian observatory seemed to 

 A'erify this statement, the change probably being due to the 

 presence of magnesium in unusual amount. 3 A, July 20, 

 1872,27. 



RESULTS OF THE BEITISH ECLIPSE EXPEDITION. 



The Eclipse Committee of the British Association reported 

 at the last meeting that, in response to the request of the as- 

 sociation, the government had sfiven 2000 to aid in the Avork. 

 The Melbourne expedition failed from bad Aveather, but the 

 Indian expedition Avas successful. The observers selected A'a- 

 rious stations in Southern India, along the line of totality, 

 and at one place only was the eclipse obscured by clouds. It 

 Avas demonstrated that hydrogen exists at 8' or 10' at least 

 above the sun. It Avas also proved that there Avas strong 

 radial polarization of the corona. Some photographs Avere 

 taken, chiefly at the expense of Lord Lindsay, and these pnyved 



