THE ERUPTION IN THE STRAITS' SETTLEMENTS 

 AND THE EVENING GLOW. 



By R. von Lendenfeld, Ph.D. 



The result of the so extremely carefully collected data referring 

 to the connection between the eruption of Karakatoa, and the 

 spreading of the evening glow, for which we are indebted to 

 Professor Smith, of our University, is expressed by this author in 

 the fellow ing manner : — " We are driven therefore to conclude 

 that the dust, if dust is really the agent in question, must have been 

 meteoric, and had its origin outside our earth." 



After this it would appear as if the data collected by Professor 

 Smith, were not favourable to the hypothesis that the dust could 

 be the volcanic dust of Karakatoa ; but the data collected, on the 

 contrary pi'ove convincingly, that Karakatoa was the centre of 

 distribution of the evening glow, and that these set in two days 

 after the eruption took place. 



I do not intend in this paper to dwell in detail on the cause of 

 the evening glow, and take it as granted, that the cause must be 

 ascribed to fine particles floating in the air. There is a dispute 

 whether these particles are ice-crystals or dust. If they were ice 

 one must be able to discern those rings around the sun which 

 always make their appearance when the sunlight is transmitted 

 through clouds of ice-crystals. The radius of such rings which I 

 have very often had occasion to observe during my Alpine expe- 

 rience is always 23°. Such rings have been observed of late in 

 Europe, but not more frequently than in other years, and I think 

 therefore, I am justified in considering dust as the cause of our 

 glorious sunsets. 



