20 ANNIVERSARY ADDRESS. 
on the morning of December 2 the same magnificent colour flooded 
the eastern sky long before the dawn. I understand that at other 
places also, dust from the atmosphere has been collected, more or 
less resembling a volcanic product. 
But the argument chiefly relied on is the fact that the splendid 
colouring on the twilight skies began to be observed immediately 
after the great eruption, and that the phenomena seemed to spread 
from Krakatoa asa centre. A careful examination, however, of 
recorded dates makes this last fact very doubtful; and in regard 
to the former, I have been assured by Mr. Baracchi of the Mel- 
bourne Observatory that exactly the same atmospheric appearances 
were frequently seen by him at Port Darwin as early as February 
of last year. Of course Krakatoa had nothing to do with these. 
The evidence obtained from a comparison of dates is open to a 
good deal of uncertainty, inasmuch as in many cases the first 
appearance of the colours was not noted or has not been definitely 
published. Even here in Sydney I am unable to fix the date of 
first appearance, nor have I been able to obtain definite first dates 
for Melbourne or Adelaide ; but if we can determine within even 
a few days the time of first appearance at a considerable number 
of places, we may be able to judge how far the eruption of Kraka- 
toa might account for the necessary distribution of dust. 
The earliest date of the abnormal appearances that I can find 
(leaving out of view for the present the case of Port Darwin) is 
August 28, at the Seychelles, and on the same date at Karachi, 
the former place being 3,000 miles west of Krakatoa, and the 
latter about as far to the north-west, the two places being about 
2,000 miles asunder. The great eruption occurred on the after- 
noon of August 26, through the following night, and during the 
forenoon of the 27th, and we are at once met with the difficulty 
of conceiving how dust could travel so rapidly. We have certainly ~ 
no reason to suppose that the higher aerial currents ever move 
so fast. If it should be supposed that the earth’s rotation had 
anything to do with it, then we are confronted with a record at 
Yokohama, on the 29th, 3,200 miles to the north-east ; and at New 
