1893.] Report of die Joint Solar Eclipse Committee. 29 



photographs, on three times the scale, by means of a negative en- 

 larging lens by Dallmeyer. 



2nd. Photographs of the surroundings of the Sun by means of a 

 prism in front of the object glass (prismatic camera). 



3rd. Photographs of the spectrum of the corona by slit spectro- 

 scopes. 



The West African Expedition was placed in charge of Professor 

 Thorpe, F.R.S. Professor Thorpe, assisted by Mr. Gray and Mr. 

 Forbes, undertook the determination of the photometric intensity of 

 the coronal light on the method he used at the Solar Eclipse of 1886, 

 at Granada. A complete and satisfactory number of observations 

 were made. 



Mr. A. Fowler undertook the prismatic camera observations, using 

 a 6-in. telescope, lent by Mr. Lockyer, with a large prism in front of 

 the object glass. Mr. Fowler took six plates before and after totality, 

 and fifteen during totality. The photographs are considered by Mr. 

 Lockyer, at whose wish this investigation was made, to be of very 

 great value. 



Sergeant Kearney, R.E., had charge of the coronagraph. With 

 the Abney and Dallmeyer lenses and a double camera, eleven pictures 

 of the corona were secured, and these are of a most satisfactory 

 character. 



Captain E. S. Hills, R.E., undertook the slit spectroscopes, and 

 obtained two excellent photographs. 



Mr. A. Taylor and Mr. Shackleton formed the expedition to 

 Brazil. The coronagraph was placed in the charge of Mr. Taylor, as 

 well as the slit spectroscopes, to be used if the necessary local help 

 could be obtained. Twelve photographs of the solar corona were 

 obtained, of a similar character to those obtained in Africa, and 

 directly comparable with them as regards exposure, density, and 

 detail of the coronal structure. Most of these coronal plates have 

 Captain Abney 's density squares impressed on them for determining 

 the density of the photographic image. Two photographs with the 

 slit spectroscopes were obtained. 



Mr. Shackleton, with an arrangement somewhat similar to that 

 employed by Mr. Fowler, took a large number of photographs ; these 

 are only less valuable than the African photographs in that the 

 instrument employed was on a smaller scale. 



The air at Fundium was hazy. At Para-Guru the observations 

 were made under peculiarly fortunate circumstances, as the Sun was 

 clear of clouds only for a short time about the time of the Eclipse. 



Generally speaking, the results obtained are of a most satisfactory 

 character. The photographs taken at each station provide a large 

 amount of material to work upon, particularly those by the prismatic 

 camera. From the distance apart of the two stations and the dupli- 



