MR. J. MARTIN ON THE TERRACES OP EOTOMAHANA. 165 



13. The Terraces of Eotomahana, N. Z. By Josiah Martin, Esq., 

 F.G.S., Auckland, N. Z. (Eead February 9, 1887.) 



The destruction, by explosion connected with, the eruption of 

 Tarawera, 10th June, 1886, of the world-renowned Terraces of 

 Eotomahana invests with a melancholy interest the subject of this 

 paper. A calamity so complete and overwhelming that not a 

 vestige of these magnificent monuments of Nature's architecture 

 remains to mark their site, has called forth expressions of sincere 

 regret, not merely from the inhabitants of New Zealand, but also 

 from every student of Nature's phenomena, every lover of the 

 picturesque and beautiful, as well as from every casual visitor to 

 this wonderful district. 



As the chief centre of attraction to tourists through the Hot-Lake 

 district, the Terraces of Eotomahana have been frequently described. 

 Poets, men of science, and historians have endeavoured to express 

 in varied language the impressions which these unique structures 

 have produced upon them, while painting and photography have made 

 known to some extent their delicacy of colour and variety of form. 

 Most of the writers have, however, admitted their inability to 

 give, from a rapid survey of the whole, more than a brief and 

 incomplete description. In fact nothing beyond a generalized or 

 vague idea could be acquired, except by a prolonged residence on 

 the spot, a close familiarity with the place in all its varying aspects, 

 a continuous study of the marvellous range of phenomena, and an 

 intimate acquaintance with and patient observation of their 

 periodicity and more salient characteristics. 



The largest and most important structure, but lately so well 

 known as the White Terrace, was of very recent geological formation. 

 Its origin, the Terata Geyser, was situated in a crater-like hollow 

 near the centre of a conical hill of steaming and partially decom- 

 posed felspathic tuff on the south-east side of the warm lake Eoto- 

 mahana. Outspreading fan-like from its cauldron, 100 feet above 

 the lake, and descending by terraced steps of white sinter in a sector 

 of 60° to a broad fiat of indurated mud, it encroached upon the lake 

 with a wide sweeping curve measuring 800 feet (see fig. p. 167). 

 The distance from the apex to the frontage was equal to a radius 

 of 800 feet, and the measurement gives an area of about 320,000 

 square feet or about 7| acres. 



The T errace was divided by marked differences of structure and 

 elevation into : — 



1. The Upper Terrace, with its long horizontal lines of cups 



steaming and overflowing with hot water. 



2. The Middle Terrace, with its massive steps and shaggy fringes 



without basins or receptacles for the overflow. 



3. The Lower Plateau, a series of shallow basins and wide level 



platforms. 



