The herald and mail. [volume] (Columbia, Tenn.) 1873-188?, 1877-08-10
TIE GREAT SEA-WAYE.
Scientific Explanations of the Recent
UpheaVaI in the Pacific.

|
recent earthquake at Peru, swept acros
the Pacific to the Sandwich islands, al
fords fresh illustration of the vital energ1
which still pervades the frame of ou
earth. If those theories be sound accord
ing to which each planet during its ex
treme youth is as a sun glowing will
fiery heat, and in extreme old age is, lik,
our moon, cold (save where the suns ray
pour upon it), even to its very centre
we should regard the various portions O
the middle age of planet as indicating
more or less of vitality according as the
signs of internal heat and activity were
greater or less. Assuredly, thus viewing
our earth, we have no reason to accept
the melancholy doctrine that she is ap.
preaching the stage of planetary decrep.
itude. She still shows signs of intense
vitality, not, indeed, that all parts of heI
surface are moved at this present time by
what Humboldt called "the reaction OF
ber interior" In this respect, doubtless
changes slowly take place, the region ei
disturbance becoming after many centu.
ries a region of rest, and vice versa.
But regarding the earth as whole, we
find reason for believing that she still has
abundant life in her. The astronomer
who should perceive, even with the aid
of the most powerful telescope, the signs
of any change in another planet (Mars,
| for example, our nearest neighbOr among
the superior planets), the progress of the
| change being actually discernible as he
watched, would certainly conclude that
that planet was moved by mighty inter.
nal forces. Now, it is not too much to
say, though at first it may perhaps seem
so, that the mighty sea-wave which, on
MAY 10, rushed in upon the shores of the
group of Sandwich islands, would have
been discernible from Venus, supposing
an observer there had been watching the
earth with telescope as powerful as the
best yet made on this earth. The wave
was caused, as we know, by tremendous
disturbance in Peru a few hours earlier
Here, at least, was the centre Of subter-
ranean action, for land wave also travel
ed from that region along the Pacific
coast of Mexico, and was felt in the Sand
wich isles, where the Kilanea volcano was
set in motion almost at the same time
that the sea-wave came in. But there
can be no doubt whatever that, as in the
case of the great Peruvian earthquake of
August, 1868, the sea-wave had its origin
not in the local subterranean disturb
ances, but in the great upheaval by which
Iquique and other places were destroyed.
We shall, no doubt, hear before long, as
in that case, of the arrival of the great
wave at the Samoa isles, at the japanese
archipelago, on the shores of New Zea-
land, Australia, and so forth. Now, the
great circular wave which spread on May
10th last from the Peruvian shore as
centre, athwart the entire Pacific, was
probably not felt by a single ship in the
open sea, any more than the still vaster
wave of the 18th and 18th of August,
1868, and for the same reason. With
height of ssme fifteen feet (or thirty feet
vertical difference between crest and hol-
low, the wave had vet so gentle a slope
that, though it rushed at the rate of three
or four hundred miles an hour across the
Pacific, the rise and fall of ship upon its
surface would be altogether impercep-
tible. The great sea-wave, as Mallett
long since pointed out, consists, in the
deep ocean of a long, low swell of enOr-
nous volume, having an equal slope
before and behind and that so gentle
that it might pass under a ship without
being noticed" And we are told, in fact,
by modern writers that during the rush
of the great sea-wave across the Pacific on
Aug. Is, II, 1868, though where the
wave reached island shores it seemed as
though the land were first sinking bodily |
into the ocean and then rising bodily out |
Of it, "there was not one among the !
htindreds of vessels which were sailing |
upon the Pacific when it was traversed |
by the sea wave in which any unusual |
motion was perceived"
How, then, it may be asked, can we |
suppose that wave which was not per-
ceiYed by those actually sailing upon the |
pecan traversed by it, could have been
visible with suitable telescope power
from a distant planet? The very circum-
stance which rendered the rise and fall of
ships upon the sea-waves of 1868 and of
ast May imperceptible, assures us that
The progress of the wave would so have
been visible. Besides its enormous range
N length, for when it struck the Sand
Hich isles its crest must have formed the
lrc of great curve, having for radius
5he distance of sixty-three hundred miles,
separating that group from Peru, the
wave had great breadth, otherwise, its
height being about thirty feet, the rapid
advance of the wave would have caused
.apid rise and fall, instead of a slow mo-
ion only discernible along the shore
ines. Probably the distance from val
,rest of the wave, was not less than two
hundred miles in the open sea. So far
IS mere dimensions, then, are concerned,
he great wave would certainly have
yeen visible from a planet placed as
Venus is when most favorably situated
or observing the earth. To show this, it
S only necessary to point out that Venus
s then much nearer to us than Mars ever
IL ~. Of 10 hT1t
about forty-fve hundred miles, while the
radius of the great wave, when it reached
5he Sandwich isles, was fully six thou
and miles. and that its probable breadth
If two hundred milesvery far exceeds the
breadth of many of the wellknown
upon the planet Mars.
But it may be asked how the wave
would become discernible at all viewed |
as it were, from above. How sheuld an /
observer in Venus know that the highest |
part of the wave was thirty feet or so near |
,r to him than the hollow Of the valleys on |
either side OF it? The way in which the |
wave would become visible corresponds |
IN some degree to the way in which those
strong radiatious which extend from sew
eral of the lunar craters are visible,
though they have very little elevation, !
cast no perceptible shadows, and are !
manv of them undiscernible when other |
lunar features are clearly seen, and be-
come discernible only when those other |
features arc scarcely visible at all. I'm
der the suns rays, the two opposite faces
IF the advancing waves would be differ |
entity illuminated. One face, a hundred
miles broad, be it remembered, would
catch the light more fully than the ocean
rs vet undisturBed, while the other |
would catch the light less fully. Thus
the mighty arc of the wave would appear
as a double arc, one half of its breadth
being bright, the other relatively dark.
We do not say that the wave would be
very striking or obvious feature of tho
earth's disc as seen from Venus, but that
il would be discernible under the same
telescope power which the Herschels,
I asset. Rose, and others have applied to /
the celestial objects as seen from the
earth's disc we have little doubt. II 50,
since not only would it be perceived as
new feature, but also its molten across
the Pacific be traceable, and the tran
sience of the phenomenon quickly recog-
nized, it would afford observers on that
planet the clearest evidence of the ac-
tiyity OF subterranean forces within our
earth. Those among the observers liv-
uyhO vyara not pOutPltt