"Read it aloud," said he, indicating a column with his finger.
"I'd be glad to hear it again, for I am not sure now that I have
the man's meaning clear in my head."

This was the letter which I read to the news editor of the _Gazette_:--

"SCIENTIFIC POSSIBILITIES"

"Sir,--I have read with amusement, not wholly unmixed with some
less complimentary emotion, the complacent and wholly fatuous
letter of James Wilson MacPhail which has lately appeared in
your columns upon the subject of the blurring of Fraunhofer's
lines in the spectra both of the planets and of the fixed stars.
He dismisses the matter as of no significance.  To a wider
intelligence it may well seem of very great possible
importance--so great as to involve the ultimate welfare of every
man, woman, and child upon this planet.  I can hardly hope, by
the use of scientific language, to convey any sense of my
meaning to those ineffectual people who gather their ideas from
the columns of a daily newspaper.  I will endeavour, therefore, to
condescend to their limitation and to indicate the situation by
the use of a homely analogy which will be within the limits of
the intelligence of your readers."

"Man, he's a wonder--a living wonder!" said McArdle, shaking his
head reflectively.  "He'd put up the feathers of a sucking-dove
and set up a riot in a Quakers' meeting.  No wonder he has made
London too hot for him.  It's a peety, Mr. Malone, for it's a
grand brain!  We'll let's have the analogy."

"We will suppose," I read, "that a small bundle of connected
corks was launched in a sluggish current upon a voyage across
the Atlantic.  The corks drift slowly on from day to day with the
same conditions all round them.  If the corks were sentient we
could imagine that they would consider these conditions to be
permanent and assured.  But we, with our superior knowledge, know
that many things might happen to surprise the corks.  They might
possibly float up against a ship, or a sleeping whale, or become
entangled in seaweed.  In any case, their voyage would probably
end by their being thrown up on the rocky coast of Labrador.  But
what could they know of all this while they drifted so gently day
by day in what they thought was a limitless and homogeneous ocean?

Your readers will possibly comprehend that the Atlantic, in this
parable, stands for the mighty ocean of ether through which we
drift and that the bunch of corks represents the little and
obscure planetary system to which we belong.  A third-rate sun,
with its rag tag and bobtail of insignificant satellites, we
float under the same daily conditions towards some unknown end,
some squalid catastrophe which will overwhelm us at the ultimate
confines of space, where we are swept over an etheric Niagara or
dashed upon some unthinkable Labrador.  I see no room here for
the shallow and ignorant optimism of your correspondent, Mr.
James Wilson MacPhail, but many reasons why we should watch with
a very close and interested attention every indication of change
in those cosmic surroundings upon which our own ultimate fate
may depend."

"Man, he'd have made a grand meenister," said McArdle.  "It just
booms like an organ.  Let's get doun to what it is that's
troubling him."

The general blurring and shifting of Fraunhofer's lines of the
spectrum point, in my opinion, to a widespread cosmic change of
a subtle and singular character.  Light from a planet is the
reflected light of the sun.  Light from a star is a self-produced
light.  But the spectra both from planets and stars have, in this
instance, all undergone the same change.  Is it, then, a change
in those planets and stars?  To me such an idea is inconceivable.
What common change could simultaneously come upon them all?  Is
it a change in our own atmosphere?  It is possible, but in the
highest degree improbable, since we see no signs of it around
us, and chemical analysis has failed to reveal it.  What, then,
is the third possibility?  That it may be a change in the
conducting medium, in that infinitely fine ether which extends
from star to star and pervades the whole universe.  Deep in that
ocean we are floating upon a slow current.  Might that current
not drift us into belts of ether which are novel and have
properties of which we have never conceived?  There is a change
somewhere.  This cosmic disturbance of the spectrum proves it.  It
may be a good change.  It may be an evil one.  It may be a neutral
one.  We do not know.  Shallow observers may treat the matter as
one which can be disregarded, but one who like myself is
possessed of the deeper intelligence of the true philosopher
will understand that the possibilities of the universe are
incalculable and that the wisest man is he who holds himself
ready for the unexpected.  To take an obvious example, who would
undertake to say that the mysterious and universal outbreak of
illness, recorded in your columns this very morning as having
broken out among the indigenous races of Sumatra, has no
connection with some cosmic change to which they may respond
more quickly than the more complex peoples of Europe?  I throw
out the idea for what it is worth.  To assert it is, in the
present stage, as unprofitable as to deny it, but it is an
unimaginative numskull who is too dense to perceive that it is
well within the bounds of scientific possibility.

        "Yours faithfully,
             "GEORGE EDWARD CHALLENGER.