22 
C. G. THORP, M.B., C.M. : 
present moment, and liable to be displaced if at any time a better 
explanation were forthcoming, or more convincing proof, of their 
meteoric origin were found.* 
Their formation has, in my opinion, been spread over a 
considerable geological epoch, as they occur in Victoria and 
Tasmania, in what are believed to be late Tertiary or early 
Quaternary deep leads, while in Western Australia they are 
found upon the surface of the sand plains, or the mud of lakes, 
often with a perfectly clean glazed surface showing no sign of 
wearing by blown sand, as so many others do, and difficult to 
believe not to be of very recent origin. In fact, no valid reason 
can be adduced against the supposition that in all probability 
they are falling to-day as they have fallen from time to time 
through all these many years. By this I do not wish it to be 
understood that in the Eastern States Australites are found only 
in the deep leads, and in Western Australia only on the surface. 
In all the Eastern States, where they are found at all, they occur 
also on the surface, sometimes on the tops of hills ; while in 
Western Australia they may be met with below the surface. 
One would think that those found on the tops of hills must be 
recent, or comparatively so, at any rate, much more recent than 
those in the deep leads, as the hills themselves must have altered 
since the time of the deposit of those in the old river beds. This 
is proved by the denudation of the hills necessary to fill up the 
latter. Such ancient valleys perhaps now constituting hills in 
the altered configuration of the srrrface. 
Is it conceivably possible, even if we eliminate the effect of 
erosion, that an Australite could lie on the surface, on the top 
of a hill or eleswhere, since Tertiary times without being destroyed 
by moving stones, hot and cold weather, wind, bush fires, kicks 
of animals, or other accidents, even if it escaped being picked 
up by an emu for its crop, or by an aboriginal medicine man as 
a charm ? Please remember this when I describe to you the 
beautiful hollow Australites that are now in the Melbourne 
Museum (Plate XVIII, Figs. I and 2), and I will ask you whether 
they could have remained unbroken on the surface since Tertiary 
times or indeed for very many years. This is making no allowance 
for the effect of weathering on the Australite itself, which in a 
few years may amount to little, but as it is scarcely necessary 
for me to remind you, we are not speaking of a few years, but 
possibly half a million — a period we can scarcely imagine. 
It does not matter from what point of view we regard it, 
an Australite on the surface cannot have been deposited at the 
* 1 have not mentioned what are called Fulgurites, which are believed 
to be due to the fusion of sand by the heat generated by lightning discharging 
at that spot, as they consist apparently of a rough tube and do not resemble 
in any way the beautiful regular Australites or even Moldavites. 
