<h2 class="nobreak" id="CHAPTER_VIII">CHAPTER VIII</h2>
<h3>THE EARTH AT ITS BEGINNING</h3></div>
<p>If we look up at the sky with the eye of knowledge
we can read in the celestial objects with which it is
strewn something of the history of our earth. We
can only read it dimly even with the aid of the greatest
telescopes, and it is quite possible that in some respects
we may read it wrongly. Let us, however, consider what
the eye and the telescope will reveal to us. The eye will
see the Sun—a great ball, into which the earth might sink
without greatly altering the Sun's appearance, and surrounded
with flaming gases hotter than the hottest furnace
man has ever been able to contrive. In that heat
every solid thing on the earth would melt and be turned
into vapour. The eye will also perceive the Moon—another
ball, much smaller than the earth, surrounded
by no gases at all, having as far as can be seen no water;
and being so cold during its long nights that all gases
and liquids of which we know would be frozen solid there.</p>
<p>The eye can also see a myriad of stars of varying
brightness, but for the most part only thus distinguishable.
If the telescope be now called in to aid, the eye
will, however, be able to discern differences and distinctions
<span class="pagenum" id="Page_91">-91-</span>
in the stars. It will see that some are balls like the
Earth, the Sun, and the Moon. If these balls are studied
attentively we shall discover that one of them, Jupiter, is
a great deal hotter than the earth, though a great deal
cooler than the Sun; and that another of them, Mars, is
a great deal colder than the earth, but a great deal
warmer than the Moon. Perhaps we might now begin to
surmise that the Sun coming first, Jupiter next, the Earth
next, Mars next, and the Moon last, were all like stages
in the history of one of these balls; and that, for
example, any one ball began by being as hot as the Sun,
and ended, after passing through stages like Jupiter, the
Earth, and Mars, in being as cold and lifeless as the
Moon.</p>
<p>But if one had a very good telescope, and could
examine those more distant specks of light which we call
stars, we perhaps could spy a little earlier into the history
of these great balls. For example, among the blazing
lights of the heavens—the stars which we know to be
suns—there are others which are not balls at all. There
are the Pleiades, for instance, of whom the Prophet Amos
wrote, "Seek Him that maketh the seven stars and
Orion" (Amos v. 8). The seven stars (in the Authorised
Version rendered Pleiades),<SPAN name="FNanchor_4" href="#Footnote_4" class="fnanchor">[4]</SPAN> when seen through a great
telescope, are caught in a mesh or a veil of something
that may be starry matter, but of the exact nature of
<span class="pagenum" id="Page_92">-92-</span>
which we are uncertain. In other parts of the sky there
are great masses of this starry mist; and to these bright
patches astronomers have given the name of "nebulæ."
The most wonderful of them all is the great nebula in
Orion;<SPAN name="FNanchor_5" href="#Footnote_5" class="fnanchor">[5]</SPAN> and one of the most beautiful is the great spiral
nebula of Andromeda. These objects are not only wonderful
and beautiful; they also give us a hint as to what
might have been the earliest state of our earth, and of
the Sun itself in those almost inconceivably distant ages
before order took the place of chaos.</p>
<div class="footnote">
<p><SPAN name="Footnote_4" href="#FNanchor_4" class="label">[4]</SPAN> It has been cogently suggested that by the "seven stars" the
biblical writer meant the constellation of the Great Bear; but
Mr. E. W. Maunder, <span class="allsmcap">F.R.A.S.</span>, of Greenwich Observatory, is of opinion
that the Pleiades were signified.</p>
</div>
<div class="footnote">
<p><SPAN name="Footnote_5" href="#FNanchor_5" class="label">[5]</SPAN> "God maketh Arcturus, Orion, and Pleiades, and the chambers
of the south" (Job <span class="allsmcap">IX.</span> 9).</p>
</div>
<p>Let us ask the reader to imagine what would take place
if the earth were to come into collision with another
planet. Some of our readers, at any rate, will know that
the Sun and all its planets—the earth among them—is
moving swiftly to some unknown destination among the
stars.<SPAN name="FNanchor_6" href="#Footnote_6" class="fnanchor">[6]</SPAN> Suppose that some great planet, not of the Solar
System, barred our path. We should not be taken wholly
unawares, for astronomers would know of the approach of
the star and our earth to one another months, and perhaps
years, beforehand. That would be because the light of
the Sun falling on it would be reflected, just as the reflection
of the Sun's rays light up the Moon for our eyes. If
the strange planet were a very large body, like the sun
for bigness, it would become visible far beyond the confines
of the Solar System. It might first be taken for
a new star such as sometimes blazes up in the sky and
<span class="pagenum" id="Page_93">-93-</span>
then sinks into darkness again. But its steadiness would
make it an object of suspicion. There would be another
brief period in which it might be taken for a comet; but
comets have a light quite different from that of reflected
sunlight. So that anxious expectation would be dissipated,
and the world would begin to recognise the monster
for what it really was. If its size were the same as
that of the Sun, then it would first become visible to us
when 15,000,000,000 miles distant,<SPAN name="FNanchor_7" href="#Footnote_7" class="fnanchor">[7]</SPAN> or let us say 1600
times farther away from us than we are from the Sun.
We and it would approach slowly at first. It would be
nearly ten years before the distance had been reduced to
6,000,000,000 of miles, and the intruder had begun to
be visible to the naked eye. In fourteen years it would
have reached the outer edge of the Solar System, and
would be the brightest star in the heavens. In another
year it would be twice as bright as Venus at her brightest,
and would be coming nearer with appalling swiftness.
In less than two months it would be as near the Sun as we
are. In a week more it would have plunged into the Sun
at the rate of 400 miles a second, and in the awful heat
born in that collision, Sun and earth and planets would
be molten, and the Solar System overwhelmed</p>
<div class="poetry-container">
<div class="poetry">
<div class="stanza">
<div class="verse indent0">In unremorseful folds of rolling fire.</div>
</div></div>
</div>
<div class="footnote">
<p><SPAN name="Footnote_6" href="#FNanchor_6" class="label">[6]</SPAN> It is usually supposed that this movement, amounting to
perhaps ten miles a second, is in the direction of the constellation of
Vega.</p>
</div>
<div class="footnote">
<p><SPAN name="Footnote_7" href="#FNanchor_7" class="label">[7]</SPAN> See an article by Mr. Ellard Gore in <i>Knowledge</i>,
November, 1905. The object would not be visible at this distance except
through large telescopes.</p>
</div>
<p>Suppose that this catastrophe were to take place.
Would that be the end of all things? No. Out of the
fiery mist many millions of miles across—like one of those
<span class="pagenum" id="Page_94">-94-</span>
great nebulæ which the telescopes reveal to us—order
would be evolved. Two things would at once begin to
happen, since in the Universe nothing stands still. The
fiery mist would be giving out heat all about it, sending
out heat-waves as a fire or a red-hot poker will do. The
red-hot poker cools; so, too, would the fiery nebula.
Then the nebula would begin to condense; not quite in
the same way that a cloud of steam does, for it would be
whirling all the time, and its fiery particles would be all
trying to fall inwards, just as anything dropped from our
hands tends to fall towards the centre of the earth. As
this whirling mass of gas condensed some great masses
of it would become detached, and would begin to enjoy
separate existences of their own.</p>
<p>Let us imagine, for the sake of argument, that a mass
of gas vast enough, when it condensed, to form the earth
itself became detached from the parent nebula. Suppose
we follow its history. At first it may have been a globe
hardly distinguishable from a whirling flame. In brightness
it was like the Sun, and like the Sun, it was
covered with elemental gases. It was, in fact, in its
earliest days a sphere of gas continually giving out
heat, and continually cooling, till from a sphere
like the Sun it became a ball like Jupiter. It had
an intermediate stage when its gases were condensing
into liquids, as steam condenses into water; for
though the nebula as a whole was hot it was always
travelling through cold space. Gradually the earth
became partly liquid and partly gas. For millions of
years it continued to revolve as a ball of liquid—still
<span class="pagenum" id="Page_95">-95-</span>
cooling—still being pressed very hard at its central parts
by the weight of all the gases and liquids round it, till
at last the first crust of solid matter began to form on
the liquid surface. This crust continued to thicken,
but it was subject to many appalling catastrophes and
breakages.</p>
<p>We have already used the occurrence of the tides of
the earth as an instance of the Sun's attraction. The Sun
(and the Moon) attract the waters of the earth, pulling
them up towards themselves. So would they also attract
the molten materials of which the early earth was composed.
The liquid mass would be continually surging
like a tide against its wall of solid crust, and the liquid
would now and again burst through. There must have
been a time when the thin solid crust covering the molten
interior became, owing to the solidification and contraction
of the crust, much too small to contain the
liquid material. The lava would then break through,
and would form huge craters, not unlike some of those
which we see on the Moon. We can faintly imagine these
terrible outbreaks in which the molten tide rose not
thirty or forty feet but many miles high!</p>
<p>Later, after some relief had been given by these outbreaks
and the crust thickened, the interior regions of the
earth by cooling shrank away from the solid shell, which
was now too large. This solid shell being insufficiently
supported sometimes caved in, and other great outflows
of lava resulted. These lava floods dissolved the original
solid shell whenever they came in contact with it. The
earth probably once had gigantic craters like those which
<span class="pagenum" id="Page_96">-96-</span>
we can see in their extinct form on the Moon; but
they were destroyed by these outflows of lava of which
we have spoken.</p>
<p>Then, still cooling, the earth's crust grew thicker and
thicker. The great outflows and eruptions of molten
elements from underneath grew fewer, and more liquid
elements cooled into solids, and more gases condensed
into liquids. There was another thing happening of
which, as conscientious recorders of the history of the
earth's geology, we must take note; and it is that in
those early days meteorites were falling on the earth
in vastly greater numbers than they do to-day. Meteorites
are masses of cooled rock flying through space which
still occasionally fall on the earth, and specimens of them
are still to be found, many of them preserved in museums,
such as the Natural History Museum in Cromwell Road,
London. But the earth in its path has swept most of
them up, as the housemaid's dusting-pan collects the
fragments of dust. When the earth was young there
were incomparably more fragments to collect, and they
fell on the earth like rain.</p>
<p>Meanwhile the cooling water vapour became the
oceans; clouds and rain and cool winds and eventually
snow and ice became possible; and the hardening
lavas, or fire-born rocks, became subject to their influences,
till above them were raised the stratified rocks, of which
we have spoken in our earlier chapters, and the lineage and
descent of which is part of the study of geology. On the
earth most of the traces of its earlier history have been
removed, but there are some signs of them perceptible to
<span class="pagenum" id="Page_97">-97-</span>
the comprehending eye. The earth is probably seamed
with great cracks that do not now reach to the surface,
but which are indicated by the presence of chains of
volcanoes. The volcanoes of the great chains of the
Andes lie along a straight crack reaching from Southern
Peru to Terra del Fuego, 2500 miles in length. The
volcanoes of the Aleutian Islands lie along a curved track
equally long. Other shorter lines of volcanoes are very
numerous, and since countless others existed in former
times, the cracks in the earth's crust must be exceedingly
numerous. There is one crack which comes to the surface
in various places in Eastern Asia and Western Africa,
and stretching from the Dead Sea to Lake Nyassa, reaches
the enormous length of 3500 miles.</p>
<p>From this brief sketch of the formation of the earth,
its progress and processes, and from the hints which the
volcanoes and earthquakes of to-day afford us, we may
obtain some idea of the underworld that lies far beneath
our feet. Not much, however, for we are ignorant of the
actual conditions which exist towards the centre of the
earth. But there seems a strong case for supposing that
there is an outer solid crust of earth and an inner
molten core of very great heat.</p>
<hr class="chap x-ebookmaker-drop" />
<p><span class="pagenum" id="Page_98">-98-</span></p>
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