606 Proceedings, 



Abstract. 



This paper contained a series of observations and measurements taken 

 at Rotomahaua in November, 1883, and November, 1885, giving the most 

 minute and careful details of the structures lately known as the White and 

 Pink Terraces, and of the phenomena of thermal activity there exhibited. 



The result of these observations was in favour of the theory that the 

 activity of the Terrace geysers had been gradually increasing ; having 

 been in their initial form steam vents, which had decomposed the tufaceous 

 rocks into felspathic mud and clays, which with increasing activity became 

 converted into a silicious cement ; the fundamental structure of the Ter- 

 races being due to the deposit in a plastic condition of the material 

 removed from the cauldron, subsequently indurated by the percolation 

 through the mass of the intermittent silicious overflow. 



The paper was illustrated by a series of photographs, taken and pre- 

 pared by Mr. Martin, which were afterwards exhibited by lime-light. 



Tenth Meeting : ^th October, 1886. 

 Professor F. D. Brown, President, in the chair. 



Mr. A. J. Vogan gave a lecture entitled "Eeceut Explorations 

 in New Guinea," being an account of the results obtained by the 

 recent expedition sent out under the auspices of the Geographical 

 Society of Australia. 



Eleventh Meeting : IQth October, 1886. 

 Professor F. D. Brown, President, in the chair. 



Papers. — 1. " Notice of the Discovery of Moa Remains on the 

 Great Barrier Island," by S. Weetnian. {Transactions, p. 193.) 



2. "On the New Zealand Species of Coprosma," by T. F. 

 Cheeseman, F.L.S. {Transactions, p. 218.) 



3. " Ornithological Notes," by A. Keischek, F.L.S. {Trans- 

 actions, p. 184.) 



4. " Kahikatea as a Building Timber," by L. J. Bagnall. 



{Transactions, p. 577.) 



A long discussion took place, in which the value of kahikatea as a 

 building timber was fully described, and the precautious that sLoald be 

 taken in using it pointed out. 



Twelfth Meeting : lith November, 1886. 

 Professor F. D. Brown, President, in the chair. 



Papers. — 1. " Notes on a Salt Spring in the King Country," 

 by Professor F. D. Brown. 



2. "The Land and Fresh-water Shells of the Thames Dis- 

 trict," by J. Adams, B.A. {Tramaclions, p. 177.) 



