238 



Mr. H. F. Neivall 



[Feb. 9, 



corona. He had a very ingenious form of thermopile, the junctions 

 of which are represented by these black patches, which are in reaUty 

 small pieces of copper foil forming the junctions of a series of bars of 

 antimony and bismuth. There were ten of these copper pieces, and 



To Gal 



they were arranged on a disc of mica round a circle of such a size 

 that the image of the sun should just fall as shown by the full-lined 

 circle. The image of the moon covering the sun is shown by the 

 dotted lines. The two halves of the pile, five junctions in each, were 

 connected in opposite directions in circuit with a galvanometer, the 

 idea being that the moon, as it passed over the sun during totality 

 would cover up one part of the corona and expose another part, so 

 that in the course of the eclipse the effect of any heat radiation from 

 the corona would show itself first by excess on one side, and then by 

 excess on the other, all effects due to the atmosphere being eliminated. 

 The observations were to be reduced to absolute measure by com- 

 tarison with other instruments, and he had additional recording 

 phermometrical instruments completing his outfit. 



Professor Fowler's work was to be mainly in spectroscopic investi- 

 gations. He had provided a well designed installation. Those who 



