28 
C. G. THORP, M.B., C.M. : 
Again, Professor Kerr Grant shows by the aid of .figures that 
obsidian bubbles cannot be formed that will float in air, nor 
exist even at our normal surface atmospheric pressure. Without 
answering his figures, I would reply that his contention is necessary 
for the understanding and support of the bubble theory. Several 
mathematical friends whom I have consulted, and to whom I 
have submitted Professor Kerr Grant's figures, have assured me 
that they saw no reason why bubbles might not be formed, and, 
provided they were thrown rapidly to a sufficient height into 
upper ranfied atmosphere, they thought it quite possible that 
they could continue to exist there a long enough time to permit 
them to be transported to the positions in which they arc found, 
if the conditions were such as 1 detailed to them. " These con- 
ditions 1 will now explain to you. They consist of the determina- 
tion of the locality of the origin of these bodies, and the method 
of their transport to the positions where they were deposited. 
Of course, the first speculation that presented itself was to 
learn whither to look for their origin, if they were borne by the 
atmosphere and dropped where we find them. 
I had much trouble in discovering any satisfactory informa- 
tion concerning the movements of the upper atmosphere, which 
1 not unnaturally expected would be from east to west, viz • in 
the opposite direction to the rotation of the globe. As I argued 
to myself : b 
1 ‘‘ ? ei , ng somewhat outside the influence of the friction which would 
draw the lower atmosphere with the globe as it rotated, the outer atmosphere 
would tend to lag somewhat, remaining more stationary. In this wav it 
might appear as if travelling in the opposite direction, viz. ■ from the east 
and from the rate of rotation of the surface of the globe— some i 017 miles’ 
per hour — even as if travelling very fast. ' 
If the outer atmosphere only travelled io per cent, slower than 
the lower it would in effect be a wind of 104.2 miles per hour 
in the opposite diiectiou at 10 miles above the surface of the 
globe. 
I must record my great indebtedness to Mr. Cooke, the 
Government Astronomer, for getting me the latest information 
on the subject, viz. : Professor Hildebrand Hildebrandson’s 
work, as the result of thirty years' observations on the movements 
of the upper cirrus clouds, which was the accepted authority he 
informed me. J ’ 
Professor Hildebrandson stated at the Southport meeting 
of the British Association in 1903 : — 
1st. That above the Thermic Equator and belt of calms 
there existed throughout the year a current from 
the east. 
2nd. That above the trades an antitrade prevailed from 
the south-west in the Northern Hemisphere, and 
from the north-west in the southern. 
