390 
has been blown away, and that the dédris covers the 
country to a distance of many miles. The white terrace 
of pumice-sand that I saw was singularly flat-topped, and 
seemed to slope abruptly from the mountain like a huge 
embankment 500 feet high. Besides these heavy sands 
that lodged close to the fissure in the mountain side, the 
lighter dust was spread out in the form of stratified clouds, 
which were distinctly seen, at this period of the eruption, 
from Rotorua, Tauranga, and Taupo. 
“The cloud thus formed discharged its contents for the 
greater part in a direction to the eastward of the mountain, 
reaching as far as Te Teko and Fort Galatea, and to the 
westward as far as Wairoa. The earth-shocks, however, 
4, \\\Vi 
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Wy Zi 
Ly 
TSS 
Wh 
\ 
“4 
TARAWERA _ 
PINK 
TERRACE 
OS 
LAN OF THE 
| FOCUS OF ERUPTION 
| TARAWERA RANGE 
& THE GREAT FISSURE 
Scale of Miles 
Stanfordis Geog? Estab? 
during this period of the eruption do not appear to have 
been of extreme violence, or to have created much alarm 
beyond that part of the district lying in the immediate 
vicinity of the volcanic eruption ; but shortly before four 
a.m. a violent outburst of a totally different nature was 
experienced, accompanied with loud reports that reverbe- 
rated through the atmosphere to enormous distances. 
The first notice of this outbreak was an earth-shock that 
appears to have been much more widely felt than those 
previous, and chiefly in areas where hot springs occur. 
This development was attendant on the outburst of 
an immense volume of steam—carrying pumice-dust and 
fragments of rocks to an enormous altitude—which pro- 
NATURE 
ceeded from the site of Rotomahana Lake, causing the 
[ dugust 26, 1886 
formation of a dense cloud in the higher atmosphere, 
that spread in definite directions, its advancing edge 
being marked by electrical discharges of the most awe- 
striking character. At first the wind was from the south- 
east, and the inhabitants of Rotorua appear to have been 
terrified by the approach of this hideous cloud, when 
suddenly the wind sprang up from the south-west and 
arrested its progress in that direction, turning it off 
towards the north-east, at the same time condensing the 
vapour of the cloud to such an extent that the suspended 
solid matter dropped on the surface of the earth in the 
form of mud, smothering the country, and leading to the 
disastrous results experienced at Wairoa. By six am. 
the period of active eruption appears to have closed, and 
since then the display of energy in a modified form has 
also rapidly declined. 
“The following are the chief points which require 
notice in this report :— 
“T. Focus.—Tarawera Range, about 3600 feet above 
sea-level, is an isolated and very conspicuous object in 
the scenery of the Lake District. It slopes from the east 
side of Tarawera Lake—the level of which is about 1000 
feet above the sea—and previous to the eruption rose 
very abruptly. with mural precipices and columnar rocks, 
especially on its western and southern escarpments. It 
was no doubt judging from this feature that Dr. Von 
Hochstetter was led to class Tarawera Mountain with the 
Horohoro Range, as being part of his older or sub- 
marine-formed volcanic series, and a remnant of the 
great plateau (Von Hochstetter, “ Reise der Novara,” i. 
106), the surface of which denotes the original level of the 
country prior to the production of its present broken 
surface by the excavation of valleys, by the up-bursting 
of volcanic mountains, and the consequent subsidence or 
breaking-in of large cavities that are now occupied by 
lakes. He nevertheless maps Mount Tarawera as be- 
longing to his recent volcanic group, and also alludes to 
it in other parts of his work as being largly composed of 
obsidian. I have never ascended the Tarawera Range, 
but have examined its slopes and found them to be com- 
posed of lavas of a high acidic or rhyolite type, in the 
form of flows intersected by dykes, and containing, 
amongst other rocks, large quantities of compact and 
vesicular obsidian. From this I conclude that the 
mountain really is one of recent volcanic origin, belong- 
ing to Von Hochstetter’s new volcanic series, and that its 
abrupt outlines have resulted from fractures and sub- 
sidences of its flanks. According to this view it is natural 
to assume that the still-imperfectly-cooled mass of lava 
in the heart of this volcanic mountain has given rise to 
the long-continued (historically speaking) solfatara action 
at high temperatures that created the attractive wonders 
of the Rotomahana. It has been stated that no Native 
tradition exists of Tarawera having been the site of 
previous activity, but the range culminates in three 
distinct peaks, the meaning of the Maori names of which 
—according to Mr. Locke, M.H.R., and other authorities 
—clearly contradicts this assumption. This consideration 
has interest, as a sudden development of volcanic activity 
in a new locality, or in an ancient and greatly-denuded 
formation like the trachyte breccia that forms the Horo- 
horo, would have been more serious and significant than 
the mere temporary revival of the expiring energies of a 
recent focus of volcanic force. 
“TIT. The Vents.—As viewed across Rotorua Lake, on 
the 13th, from the point where the Tauranga Road 
emerges from the bush, Tarawera Range appeared to 
have quite lost its former characteristic outline. The 
deep gap dividing Wahanga, the northern peak, from 
Ruawahia, the central one, was almost obliterated, and 
the abrupt, precipitous sides of the mountain were every- 
where softened by great slope deposits of material ejected 
from the volcanic vents, consisting of stones and dust of 
a grey colour. Along the edge of the range seven distinct 
