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CONTENTS. 



Page. 



Art. XVII. — On some Building and Ornamental Stones of New 

 South Wales. By E. T. Baker, f.l.s., Curator Technological 

 Museum, and James Nangle, f.r.a.s., Lecturer in Archi- 

 tecture, Technical College, Sydney ... ... 180 



Art. XVIII. — The nature of the Large Ions in the Air. By J. A. 

 Pollock, d.sc.. etc, Professor of Physics in the University of 

 Sydney 198 



Art. XIX. — Corrasion by Gravity Streams with applications of the 

 Ice Flood Hypothesis. By E. C. Andrews, b.a., Department 

 of Mines, Sydney. Parts I, II, III 204 



Abstract or Proceedings xxi-xxix. 



