The Eclipse of 1 8 70. 855 



began ; we were all prepared for observing it, and we 

 followed its progress through the opening in the clouds 

 till at last there was only a very slender crescent of 

 the sun's disc left ; its convexity was turned upwards, 

 and its horns were nearly horizontal. It was then 

 hidden by a dense mass of clouds ; but after a time 

 they opened, and I saw the edge of the moon leave 

 the limb of the sun. The appearance of the land- 

 scape was very lurid, but by no means very dark. 

 The common people and children had a very good 

 view of the eclipse, reflected by the pools of water 

 in the streets. 



Many of the astronomers who had been in Sicily 

 observing the eclipse came to see me as they passed 

 through Naples. One of their principal objects was 

 to ascertain the nature of the corona, or bright white 

 rays which surround the dark lunar disc at the 

 time of the greatest obscurity. The spectroscope 

 showed that it was decidedly auroral, but as the 

 aurora was seen on the dark disc of the moon it 

 must have been due to the earth's atmosphere. Part 

 of the corona was polarized, and consequently must 

 have been material ; the question is, Can it be the 

 etherial medium ? A question of immense impor- 

 tance, since the whole theory of light and colours 

 and the resistance of Encke's comet depends upon 

 that hypothesis. The question is still in abeyance, 



AAi 



