A CONTRIBUTION TO THE STUDY OF AUSTRALITES. 
35 
portion of the atmosphere would be amply sufficient to reduce 
it to a molten condition even though its lessened rapidity as it 
approached the globe due to the brake power exerted by the 
friction of the opposing air were to permit it to become plastic 
again. 1 his of course is arguing on the supposition that Pro- 
fessor Kerr Grant’s premise is correct which as I have just 
stated I believe it is not. 
W e never find nor hear of anyone else finding siderites even 
resembling these shapeless Moldavites ; they always reach us 
as definite fragments of larger bodies at least as far as I have been 
able to ascertain though their surface may appear to have been 
recently fused or their mass split up. The same may be said of 
stony meteorites or aerolites as they are called. 
A siderite would conduct heat into its interior much more 
readily than a glass meteorite though still not well. The latter 
would tend rather to decrepitate or flake off from the surface, 
which may account for the curious markings on these bodies, 
which have been so minutely and laboriously described. 
I have described Australites as having a fused surface when 
newly fallen and yet maintain here that if suddenly heated they 
would chip rather than melt. This is perfectly correct. Austral- 
ites falling as the result of the collapse of their bubbles would 
start to fall slowly and increase their pace gradually ; thus the 
heat would increase also slowly and even the outside would never 
become very much hotter than just sufficient to fuse it. I 
should say even that they might chip in places while fusing 
surface as a whole hence the markings as I said before. 
If they were meteorites they would probably start, according 
to Professor Kerr Grant, at a velocity of 40 miles per second, 
which would involve a very sudden heating indeed, and they 
would be far more likely to flake than fuse. This is in entire 
support of my description of the disintegration of a falling star, 
the small ones fuse from the surface inwards, as there would be 
no great distance for the heat to diffuse into the centre the body 
would rise in temperature almost equally throughout and thus 
the surface would be able to melt and be wiped off without the 
body cracking, so they are dissipated to dust. The large ones 
may fuse on the surface and remain whole or may break up, as 
would be determined by their structures, as from their size the 
heat would diffuse more slowly. 
The time occupied by the passage of a meteorite through the 
air, even though the heat generated on the surface by the friction 
were perfectly conducted into the centre of the mass and so none 
lost, would not be sufficient to permit enough to be generated to 
entirely fuse a comparatively small body. 
Starting at 40 miles per second, as Professor Kerr Grant 
states, or even at 25 miles per second as, I am informed by 
