The Pacific commercial advertiser. [volume] (Honolulu, Hawaiian Islands) 1885-1921, 1896-08-14

/ Gated II was the right of the rest. OF
/ course the progress was slow But the
tendency was there
/ We pass rapidly over the Middle
+ Ages. Alfred the Great studied, found
! ed schools, and hoped TO see the day
/ when every man in his kingdom could
/ read. Before his time, Charlemagne
was much the same kind of a man. with
a greater kingdom TO rule
But in ali this time there is little
meat for US. About the fifteenth cen
fury there was revival of ancient
learning, the ''humanities." as they
were called, Latin and Greek
AS there are to be lectures, under
stand, on the great names between. I
shall skip, tomorrow, to Locke"
Volcanoes, continued, was DR.. Lyons
subject.
THE relative age of our volcanoes
was first. Kilauea is very young, has
built no mountain yet Mauna Loa is
older, but gives us an eruption about
once in ten years not second to any in
the world Hualalai has broken out in
the last hundred years. and can hardly
be considered extinct The next one in
age is more difficult to pick out. Is it
Mauna Kea or Haleakala? From the
fresh lava, probably the latter is the
younger. There must have been an
eruption within three hundred years
at the outside. 1t is strange we haveno
traditions on the point Lanai and Ka-
hoOlOwe are probably next, judging by
the slightness of erosion. But they are
small, and SO it is uncertain. KohaIa
West Maui and West Molokai are next
and about the same age.
East MoIokai is older, but about the
same as East Oahu. Waianae and Kau-
al are the Oldest.
Still, there are evidences of COM
paratively recent eruptions on all the
islands. While the ravines here are at
least 100000 years old, and those in
Waianae older, yet there is lava here
at the base of some of the mountains
that can hardly be older that 1000
years.
''Will they be renewed? Probably.
Can we tell when? Not certainly, but
Mauna Loa and Mount Etna have al
ways had their heavy eruptions, as far
as history shows, within few months
of each other. In fact there seems to be
a unanimity in the action of all the
volcanoes on earth that suggests COM
mon cause. A coincidence between sun
spots and heavy rains on the one hand
and volcanic activity on the other. 1t
is easy to see the connection of the
rains. The rains furnish water for the
vapor which causes the expulsion. The
connection of sun spots is not so easily
explained.
LAS we have seen, rock is formed in
two ways by igneous and by sedi-
mentary action. Igneous action builds
up. We see this in volcanoes. But that
is comparatively slight. The great
work is done in the raising of mountain
systems by the wrinkling of the earth's
crust On the other hand, the atmos-
phere and the ocean tear down. If
they alone were at work the earth
would be only a low plain just above
the ocean.
"The old definition of volcano was
burning mountain. The trouble with
this is that it is never burning, and not
always a mountain. There are three
IL g
either fiat like Mauna Loa when the
lava runs over in quantities and quite
fluid, or steep like CotopaXi and YES
uvius when the lava runs out in small
streams and not very fluid. Second
cinder cones, usually small, sort of blow
holes, and having a crater on top.
Third, tufa cones, when there is much
water and much steam is formed, car
rying out finely divided rock and de-
posting it in a sedimentary way.
You can illustrate the lava forma-
ton to your classes by making plaster
of paris into a thin paste, building up
a crater with clay or putty, and pouring
the lava in. The plaster should be
tinted with red earth or lamp black.
Clean out your crater after an eruption
and it will be ready for another.
For a cinder cone, sprinkle sand
through large pepper box in different
tints, one after another. 1t will form
a sort of irregular qualification.
ITO tell whether rock is igneous or
sedimentary, look at the crystals; they
are igneous, while bands are found only
in sedimentary rock.
ITO study a mountain, first see if it
is regular, when it will be volcanic; or
irregular, when it will probably be the
remains of a wrinkle in the crust. Next
find out the material, which you can
do by examining the sides of the ra
vines