Notea qii Austvcplites. 22~> 



fjg. 10 is an example *. ► i' Pele's Tears, cigar-shaped, and consist- 

 ing <>t' very scoria*, nms grey pumice with a smooth skin on the sur- 

 face, hut so .friable as to readily crush between the finger and 

 thumb. 



Fig. 11 is a dumb-bell shaped Pele's Tear similar to Fig. lo in 

 material. These examples of Pele's Tears are for comparison with 

 some of the forms of australites. They arc of volcanic origin, heing 

 found on the Hanks of Kilauea, Sandwich Islands, and were pre- 

 sented to me by Professor Moore, of the State College, Pennsylvania, 



r.s.A. 



Figures 1 to !) suggest that llie small australites may owe their 

 form to rotary action. There is no process or remains of such a 

 process around the periphery as would favour the theory of their 

 forming part of a bubble, and. here 1 may say that the theory that 

 .australites were the lower portions of bubbles was suggested by the 

 hollow sphere 2 inches across in the Melbourne National Museum, 

 and by other hollow examples. Further, on making sections across 

 button-shaped examples, the broken edges marked c in the photo- 

 graphic illustrations in Bulletin No. 27 of the geological Survey of 

 Victoria and the flow structure appeared to confirm this view. The 

 broken edges at c may, however, have been accidental. 



Tdie flow structure as shown in the photographic plates in the 

 above Bulletin sevm difficult to explain if australites were formed 

 by rotary action, and the relation of the rim to the core seems a 

 difficulty, for the Jjullefin. illustrations above referred to appear 

 "■to, indicate that the c-entre or core was first formed, and then the 

 rim, while the examples of small australites here dealt with appear 

 to imply the reverse, or that these bodies at the beginning were 

 •disc-like, and all rim, aijd tjiat a portion of the centre of the disc 

 was absorbed to form the core, and that this core increased in size 

 at the expense of the rim by continued rotary movement until the 

 glass became rigid. The formation of hollow spheres by a rotary 

 process also presents difficulties, and tbe presence of perfectly 

 spherical bubbles so common in the cores of australites is also diffi- 

 cult to understand if the core was rapidly rotated while yet in a 

 viscous condition. 



If these small objects were moulded by rotary movements, the 

 rotation must have been about an axis at right angles to the plane 

 of the disc, and if so then the more abnormal types such as ovoidal, 

 elongated and dipnb-bell forms must also have resulted from rotation 

 about the shorter axes of these bodies, and in planes corresponding 

 to the plane of the disc. 



