THE ERUPTION OF KRAKATOA IN 1883 239 j 



The colored suns were probably due to the absorption of certain rays 1 



of light by the volcanic dust in the atmosphere. The large corona ' 

 around the sun was first recorded by Mr. Bishop at Honolulu, on Sep- 

 tember 5, 1883, and since that time it has generally been known as 



Bishop's ring " ; the halo around the moon was noticed in the tropics J 



during the same month. These effects are referred to the lighter j 



particles of dust in the atmosphere, for in April, 1884, when most of 'i 



the coarser material had settled by gravitation, and the twilight glow^s 1 



began to fade, the corona brightened, then gradually became fainter, j 



and was last observed in June, 1886, after which the sky resumed its | 

 normal appearance. 



In conclusion, it may be said that the works on Krakatoa, referred 

 to above, contain many charts, maps, and barograms, and in short 

 form a complete record of all the phenomena caused by the eruption. 

 These works are more valuable than if they contained only the results 

 of the reports collected, for, by publishing the sources of information, 



opportunity is given to any one interested in the subject to study these, | 



and thereby form his own conclusions. When other eruptions shall | 



have been treated in the same manner, more light will be shed on some ; 



of the effects now slightly obscured, as the cause of the colors observed \ 



in the sky and the origin of the great sea waves. Although eruptions J 



have occurred in the past, exceeding that of Krakatoa both in duration | 



and in the quantity of material ejected, such a complete history of one I 



has never been written till now. This is due in part to the spread of | 



civilization over the earth, and hence the establishment of places of i 



scientific observation. As the number of such observatories will con- \ 



tinue to increase, it may be confidently predicted that the phenom- j 



ena accompanying violent volcanic outbreaks in the future will be \ 



more closely observed and more widely recorded. j 



R 



