198 PROCEEDINGS OF SECTION C. 



Professor Weinschenk* has described a shell of glass covering 

 about one-third of the surface of two Moldavites from Kuttenberg, 

 and concluded that this shell was the result of the fusion of the surface 

 during the passage of these bodies through the atmosphere. This 

 result is more in accord with the action noted on undoubted meteorites 

 which also show a somewhat similar surface fusion. 



Mr. J. B. Scrivenorf states that none of the Billitonites examined 

 by him show this surface skin, but adds that as the Billitonites occur 

 in beds of alluvium containing rolled pebbles the absence of such skin 

 is not to be wondered at. 



If we accept the-'cosmic origin of the tektites, we must conclude 

 that the conditions of their passage through the atmosphere were not 

 the same in the three cases, for the Austrab'tes must have become 

 thoroughly molten, while only the surface of the Moldavites was fused. 



The dissimilarity of the composition of the tektites from that of 

 authentic meteorites is one of the main arguments advanced against 

 the meteoritic origin of these bodies. This brings us to the origin of 

 meteorites. It is probable that they are derived from the disruption of 

 larger bodies, and if these bodies had compositions at all comparable 

 with that of the earth then we should expect a very large proportion of 

 iron, a small proportion of basic, and a very small proportion of acid 

 meteorites. Instead of arguing that because all authentic meteorites 

 are basic in character therefore the tektites cannot be meteorites, the 

 writer would be inclined to argue that because iron and basic or stony 

 meteorites fall therefore we should expect a small proportion of acid 

 meteorites also to reach the earth's surface. 



Professor Kerr GrantJ has suggested that the occurrence of the 

 tektites in the three localities is possibly due to successive returns of 

 the same meteor shower. Should this be correct, perhaps at some 

 future date the same meteor shower may again return and yield the 

 only possible positive proof of their meteoritic origin. 



It has already been pointed out that the known occurrences of 

 Australites are confined to a broad belt running approximately W.N.W. 

 through Tasmania and Southern Australia, and this type of distribu- 

 tion is what one would expect if a shower of meteoritic impinged on 

 the earth's surface. 



I have stated elsewhere that there seemed to be a somewhat pro- 

 vincial distribution of the Australites in respect to composition and 

 specific gravity. As one would naturally expect, the specific gravity 

 varies with the silica percentage so that the specific gravity of a speci- 

 men, except where modified by the occurrence of included vesicles. 



• C)ii';ralblaU f. Min. Gaol. No. XXrV, 19:)3, p. 737. 

 t G;oI. Mag. Vol. VI, 1909, p. 411. 

 j Op. cit. 



