A CONTRIBUTION TO THE STUDY OF AUSTRALITES. 
39 
and its unequal heating, and enter the tornado-like current of 
highly rarified air of the central stratum, in which also the highest 
cirrus clouds are situated, which moves continuously and with 
great velocity in a certain definite direction from one years’ 
end to the other, viz. : first towards the west then south or north, 
as the case may be, then south-east or north-east, and finally 
east, by which within two or three days at the outside they are 
transported till vertically over the continent of Australia, if 
Australites, or correspondingly north if Billitonites. By this 
time the bubbles having descended slowly and steadily into the 
dense lower atmosphere are crushed and their brittle thin globes 
chipped off the more resistant blebs in varying manners according 
to size and shape. 
The blebs drop to the earth at first slowly, then more rapidly, 
becoming gradually heated on the surface by the friction of the 
air in their passage, so that it fuses and they become covered 
with a thin glaze. That this is possible, even considering the 
comparatively high fusion temperature of their glass, is shown 
by siderites being found with their surface fused. 
These latter bodies conduct the heat from their surface only 
imperfectly, and thus would retain the cold of space in their centres, 
even when a thin layer of the surface was heated sufficiently to 
fuse and produce the glaze you see here. Their fusion temperature 
is higher, but they have a much longer and more rapid flight. 
Then, if they chance to fall on some soft spot on the globe, such 
as sand or mud, they will be preserved as we find them. 
So many of my correspondents having expressed so strongly 
their adherence to the meteorite hypothesis, and their opinions 
as to the impossibility of Mr. Dunn’s proposition, I have felt 
compelled to endeavour to show the utter futility of each and 
every argument adduced to support the idea of these bodies 
coming from extra terrestial sources. If 1 have been partially 
successful in this and in adding any extra links to the bubble chain 
of evidence I shall feel amply rewarded. 
I hope that if any have opinions, facts or arguments upon 
this subject, either in favour of or against the hypothesis now put 
forward, you will give us the benefit of them. If in agreement, 
I welcome you ; if in friendly opposition I welcome you scarcely 
less, almost more, in fact, as’ there is nothing so stimulating and 
supporting as a sound strong constitutional opposition. 
Finally, I would wish to express my obligation to many 
friends for information and advice, to the Director of the Prague 
Museum, for his exceedingly well-timed gift of Moldavites ; to 
Mr. Simpson, to Professor Ross and others for papers and specimens 
for exhibition this evening ; to the Minister for Mines of Victoria, 
for permission to use and the loan of some of the plates belonging 
