THOUGHTS ABOUT KRAKATOA. 341 



they, at all events, entertained but little doubt that the 

 dust of Krakatoa was responsible for the sunsets of 

 Chelsea. Still I notice that some members of the Com- 

 mittee seem to shrink from deliberately committing them- 

 selves to this view. Indeed, the very title of their book 

 exhibits a certain degree of caution on this point. They 

 have called it " The Eruption of Krakatoa and subsequent 

 Phenomena." The word I have italicized would not 

 improbably have been consequent had it not been for the 

 existence of some such reserve as that I have indicated. 

 But the magnificent body of information which their 

 labours have brought together will enable every one who 

 will carefully study the volume to form his own opinion 

 as to whether or not it was Krakatoa dust which painted 

 our sunsets with those glorious hues. In attempting to 

 decide this question we must first endeavour to conceive 

 the kind of evidence which would be necessary and suffi- 

 cient to establish the fact that the optical phenomena were 

 consequent upon, as well as subsequent to, the great 

 eruption. 



First of all it would be natural to ask whether the 

 existence of volcanic dust in the air could have produced 

 the optical effects that have been observed. This must 

 be answered in the affirmative. Then it would be proper 

 to inquire whether other volcanic outbreaks in other parts 

 of the world, and on other occasions, had been known to 

 have been followed by similar results. Here, again, we 

 have page after page of carefully stated and striking 

 historical facts which answer this question also in the 

 affirmative. Next it would be right to see whether the 

 sequence in which the phenomena were produced at 



