24 REPORT — 1875. 



ASTEOKOMT. 



On the Total Solar Eclipse of April 5, 1875, observed at Bangchallo {Siam). 



By Dr. J. Janssen. 



Dr. Janssen used a special telescope for the study of the corona. The results 

 obtained by the observations are as follows : — 



1. It was established that the line 1474 is infinitely more pronounced in the 

 corona than in the protuberances. This line seems even to stop abruptly at the 

 edge of the protuberances without penetrating them. The light, therefore, which 

 this line 1474 gives belongs especially to the corona. This observation is one of 

 the strongest evidences that can be brought forward to prove that the corona is 

 a real object, matter radiating by itself. The existence of a solar atmosphere 

 situated beyond the chromosphere (an atmosphere that Dr. Janssen had recognized 

 in 1871 and proposed to call the coronal atmosphere) thus receives confirmation. 



2. Height of the Coronal Atmosphere. — In 1871 Dr. Janssen announced that the 

 coronal atmosphere extended from a distance of half the sun's radius to the distance 

 of a whole radius at certain points. This assertion has been confirmed not only by 

 the direct observation of the phenomenon, but also by photography. At Dr. 

 Janssen's request, Dr. Schuster took photographs of the corona with exposures of 

 one, two, four, and eight seconds. In this series of photographs the height of the 

 corona increases with the time of exposure. The height of the corona in the eight- 

 seconds' photograph exceeds at some points the sun's radius. (It is true that 

 account ought to be taken of the influence of the terrestrial atmosphere.) 



3. As the sky was not perfectly clear at Bangchallo, Dr. Janssen was enabled to 

 observe phenomena that explain previous observations of eclipses which seemed 

 to invalidate the existence of the corona as an incandescent gaseous medium. 



On the whole the observations of April 5, 1875, have advanced us a fresh step 

 in the knowledge of the corona by bringing forward new proofs of the existence of 

 an atmosphere round the sun, principally gaseous, incandescent, and very extended. 



List of Meteors observed at Oxford. By the Rev. R. Main, F.R.S. 



Transit of Venus, December 8, 1874. 

 By the Rev. S. J. Peekt, F.R.S. , F.R.A.S. 



The remarks made refen-ed mostly to the Kerguelen Expedition, of which the 

 author had the charge. 



Some of the members of this Expedition left England on May 20, and the rest 

 on June 20, 1874. All met at the Cape of Good Hope, and proceeded thence in 

 two of H.M. vessels, the 'Volage' (Captain Fairfax, R.N.) and the 'Supply' 

 (Captain Inglis, R.N.). The Crozetswere passed with fair wind and weather; but 

 a storm encoimtered off Kerguelen delayed the landing for two days. During this 

 time many of the sheep, goats, and oxen, and other live stock taken on board at 

 the Cape were destroyed, and a large boat carried off by the waves. No injury 

 . was sustained by the instruments, except the deck thermometers, and no lives were 

 lost, 



A few days were spent in surveying the west and south coasts of Royal Sound, 

 and two excellent stations were found by the aid of Captain Bailey, of the sealing 

 schooner ' Emma Jane.' The huts and instruments were erected at once at the 

 principal station, and three weeks later at the second station. A third station was 

 occupied a few days before the transit, as it was found to be perfectly impracticable 

 to attempt observations at MacDonald Island. 



The weather generally was not so bad as we had been led to expect ; but we were 

 visited by snow-storms even in the middle of summer, and the wind blew half a 

 gale at least five days out of every seven. Still we were free from mist, and the 

 sky was fairly fine during at least part of most days. 



