360 Transactions. — Geology. 



as if the solid rock had been ripped open by the enormous force 

 oi imprisoued steam ; and iu its upper part the ashes, rocks, 

 and the ground generally for a longdistance on either side, were 

 coloured a yellowish-green, due no doubt to some of the products 

 of volcanic actic)n — such as feriic chloride. The slopes of the 

 mountain around were covered deeply by ashes and stones, and 

 near the base of it steam escaped from several cracks. As we 

 sat on the surface of the sand observing the chasm through the 

 glass, frequent shocks of earthquake caused cracks to open near 

 the rift, and steam was seen to escape in little jets, ceasing, 

 however, soon afterwards, as the cracks closed in or the loose 

 materials fell into and stopped the vents. The southern end of 

 the rift seems to be continued as a hollow right into the site of 

 Rotomakariri, which is now occupied by a crater, from which 

 rises a vast column of steam and occasionally smoke ; indeed, 

 this part seems to be one of the most active craters of the whole 

 series. Mr. Morgan, who approached this side of the crater 

 from Galatea on the night of the 14th, states that he saw a 

 great glare as of fire, and a large mass of smoke issuing there- 

 from. 



During the time we were in the district the weather was 

 most beautifully clear, with a hght south-west wind ; and this 

 allowed of a careful study through the glass of the heights of 

 Wahanga, Euawahia, and Tarawera, as seen from various points. 

 That great changes have taken place in the two latter is obvious 

 to any one who knew their former shapes and appearance. In 

 1874 we made the ascent of Euawahia on three occasions, start- 

 ing from near the outlet of Lake Tarawera, and are thus able to 

 give some description of the range prior to the eruption. All 

 those who have visited the Lake District are familiar with this 

 range, which rises out of the lake on its eastern shore by 

 gradual easy slopes, until near the summit, where a wail-like 

 mass of trachytic or rhyolitic rocks marks the division between 

 its plateau-hke top and the gentler slopes below. From the 

 northern end of "Wahanga to the southern end of Tarawera is a 

 distance of about three miles, whilst the plateau has a width of 

 perhaps a mile, broken at one mile from the north end by a 

 deep saddle, dividing "Wahanga from Euawahia. The surface of 

 the plateau was covered by immense masses of broken trachytic 

 rocks, which looked as if they had been shivered and fi-actured 

 by the action of the frost into long angular blocks of various 

 sizes. Eur.ning in all directions weie depressions or crevices 

 dividing the surfnce into hummocks, ai d making travelling very 

 difiicult; whilst occasionally a hillock formed of the piled up 

 masbes of loo^e rock rose above tlie general surface. No bigu 

 of any crater was seen, though the rocks are all undoubtedly 

 due to volcanic action. Possibly in this range we see an illus- 

 tration of one of those great masses of ejected lava described by 



