ABSTRACT OF PROCEEDINGS. xlvii, 



the application of the prismoidal formula to circularly ruled 

 quadric surfaces, was an elementary case of a much more general 

 theorem, and that a manifold infinity of analogous theorems can 

 be developed for much more complex surfaces. 



4. "Rock-holes used by the Aborigines for warming Water," by 



R. H. Mathews, l.s. 



The author showed that the natives were in the habit of 

 immersing heated stones in small quantities of water for the 

 purpose of warming it for drinking, and in some cases to assist 

 in cooking their food. 



5. "Some Aboriginal Tribes of Western Australia," by R. H. 



Mathews, l.s. 



Mr. Mathews also contributed an article on some aboriginal 

 tribes of Western Australia, describing their divisions into inter- 

 marrying sections; lists of totems, comprising animals, plants, and 

 other natural objects, attached to each of the sections, were also 

 given. The laws regulating marriage and descent were explained, 

 together with a brief outline of the structure of the language. 

 Mention was made of their legends, knowledge of the cardinal 

 points, and customs of genital mutilation, the whole concluding 

 with a comprehensive vocabulary. 



6. "Projects for Water Conservation, Irrigation, and Drainage 



in New South Wales, by H. G. McKinney, m. Inst. c.e. 



The author of this paper described at the outset the conditions 

 which are most favourable for extensive work for water conser- 

 vation and irrigation. In this connection, Lombardy, Upper 

 India, and Egypt were specially referred to, and the case of the 

 latter country was described as being the best known combination 

 -of conditions favouring successful irrigation on an extensive scale. 

 Applying to New South Wales the conditions referred to, the 

 the author proceeded to point out that the Dividing Range is the 

 only source to which we can look for sufficient water to supply 

 any large scheme. In the coastal district the rainfall is fairly 

 satisfactory; and as much of the alluvial land on the rivers is low- 



