The Hawaiian gazette. [volume] (Honolulu [Oahu, Hawaii]) 1865-1918, 1881-08-31
Descriptive Letters from the Scene
of the Late Lava Flow.

Of the Late Lava Flow.
Mr. EDITOR GAZETTE The terminus of the
Hilo lava flow is dead and fast becoming cold, and
though still object of great interest and profitable
for study. is hardly capable any longer Of furnish
ing much that is startling or sensational.
1t is not to be supposed that such an immense
amount of molten material as this eruption has
poured out will become entirely cool in short time
Experience shows that heat sufficient to boil
water may be expected to persist in the depths be-
low the black crust for long time to come, fol
months, perhaps for years. My observations OF
the present flow are as late the 18th instant, al
which time tTaversed and carefully observed 1t as
far nauka as John Halls place, about four miles
from Hilo. AT my last visit TO the flow the party
of which was one left our horses at point about
one mile below John Halls, where we found the
road covered over by the stream. From this point
we proceeded on afoot over the lava flow. The
width of the stream here Is not far from half mile
The walk mauka to John Halls is a continuous
gradual ascent.
The heat was sufficient to cause water to sizzle
in many places and the rain that fell upon the lava
soon rose in steam.
We found cracks hot enough to burn the ends of
our sticks, but fire visible; the air of the
whole area was heated by radiation and percsptiby
impregnated with sulphurous gases. Our search
was specially for "blow-holes" the existence of
which had been both asserted and denied. l saw
several places which in my opinion must have been
blow-holes not long before, but were at the time
filled in and crusted over. Not until we had
reached point about the middle of the stream, q
little makai of John Halls, did we find real live
"blow-hole." Here was ragged hole or sky-light,
perhaps eight feet by fifteen in dimensions through
which we could look directly into the immense
tunnel down which the molten lava had been flow
ing Stewards. The cooled crust of the flow, the
vaulted roof of the tunnel had at this point broken
in and allowed the observer by choosing his posi-
ton, to study with safety the operations that had
been going on within this great duct.
No flowing lava w6s to be seen.
Immediately about the hole, the air from which
was hot enough TO infiame the pieces of wood we
threw into it. the lava was black and crumbling;
but at either end and especially in the makai di-
rection whittier the molten fluid had drained of,
the color was that of the brightest flame and pieces
of black lava we threw into it soon became glow
ing red. By drawing as near as possible TO the
blow-holes at their mauka side which was their
higher edge-and also unfortunately for US TO the
leeward side, and thus exposed us to the blast of
hot air that issued from beiOw-we were able to
obtain perfect view along the course of the tun-
mel for distance perhaps Of $50 or 200 feet and in
one of them it seemed 10 me the tunnel we were
looking into at length became bifurcated and di-
vided into two channels by partition which ex-
tended from the floor TO the summit of the vault.
The floor of this tunnel was formed of huge
rounded boulders, Just such will find in any
rocky water course, and such the bed of this huge
duct had originally evidently been. One would
have thought that the intense heat would have
melted down their huge bosses and leveled their
fractory masses into one common plane. But such
not the fact and there their rounded turtleike
backs lay, glowing but unsubdued in the incande-
scent heat.
From either side of this bed arise the mighty
walls that arched inwards and met overhead to
form the covering archway, with here and there
column half In relief wrought In glowing rock, yet
strange TO say unmelted, or rather now cooled
down to a consistency capable of supporting the
immense tables of pahoehoe that formed the roof
1t seemed wonder that the rock itself was not
consumed by the awful heat and that the structure
stood for moment; and one could not but think
with horrilip Chuddpr that the vvpiuht of
bodies trampling over the roof of the cavern must
sufice TO make the internal archway collapse and
precipitable US into its consuming abyss. But we
ran and capered about over its roof with thick
of but little more than foot, or even less be-
tween feet and this fiery tunnel and it gave us
sign of yielding. BUTT is to bepresumed that
the heat decreases the mass of overarching rock
will contract and become more brittle, and Will
consequently splinter and crack and in many
places fall in. Such has evidently been the case
about the blow-holes themselves and their very
istence seems to be due to this cause.
Proceeding mauka, we found another blow hole
several hundred yards above the first which evil
IDENTIFY opened into a continuation Of the same tun-
mel. The appearance of this was much the same
as that Of the one Just described.
The mouth of each was ragged and broken, and
fallen rocks lying in the bed of the tunnel imme-
diatelY below showed clearly that the openings
themselves must have been enlarged If not entirely
caused by collapse of the roof, due to cooling.
These blowholes by the way, situated, 1t seems,
only at such portions of the tunnel as offer
siderably rapid decline for good ways below them,
and rarely or never at the foot of such decline,
nor In the comparative hollows or basins that pre-
sent themselves along the nOw. The reason for
this is evident in the fact that only at such points
could the molten fluid drain away and leave the
tunnel empty.
am informed that one or two miles above John
Halls, the roof of one of the lava tunnels has
quite extensively crumbled and fallen in thus pre-
venting its future use by the molten stream.
Wherever this has occurred new flow, should there
be another soon would at these points have to find
its way over the surface of the solicited lava or
form for itself new channels before any large
amount of the molten mass could reach the ocean
or the town of Hilo. Thus fal have spoken only
of one tunnel, the one seen by myself. But it
seems to me quite certain that flow Of such width
must have formed for itself numerous tunnels, and
such seems to be the conclusion reached by those
who have had better and later opportunities than
myself for observation. 1t would seem as If this
must be the case especially in certain level places or
hollows where the molten lava spreads out and
formes huge lake
In estimating the danger to the town of Hilo,
there are several things to be taken into consdera
ton. OF course, first and chief is the continuance
or abatement of the supply from the fountain
head far up the mountain, near Mokuaweoweo.
If this has permanently ceased the danger IS over
But supposing the discharge from this crater tore
sumo Its flow, how will the stream of lava now
poured ont the surface of which has already cooled
down and become an immense rocky bed, though
its depths still glow with ferTent heat affect the
new foodg
The view have generally heard expressed is that
it will act barrier and viii tend to divert any
new flow to the right or to the left. 1t is impossi
BE to decide this question without making an ex-
tended study of the how, and of the trend of the
ground far up towards the source of the stream
The mere cooling and falling in at various points
of the tunnel, more properly tunnels, which the
stream has already made for itself, seems to me
but small consideration to weigh against the on
wjird and downward movements of such huge
masses of molten fluid as Maunaloa has shown It
self capable of pouring out As in the past any
new flow may be depended upon to do for itself its
own tunneiing and arching over.
OF course if it finds open tunnels already made
to hand It will be much clear gain and il seems
to me that even one partly broken downward filed
up IN places though still hot the present tunnels
are would be Of great service to a new flow taking
place on the heels Of this one. Again it must be
borne In mind that the foT, nov apparently ended,
an or