a journey in other worlds-第40章
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earth。〃
It was just six terrestrial weeks since they had set out； and
therefore February 2d on earth。
〃It would be best； in any case； to start from Jupiter's equator；〃
said Cortlandt； 〃for the straight line we should make from the
surface here would be at right angles to Saturn。 We shall
probably； in spite of ourselves； swing a few degrees beyond the
line； and so can get a bird's…eye view of some portion of the
southern hemisphere。〃
〃All aboard for Saturn！〃 cried Bearwarden enthusiastically； in
his jovial way。 〃This will be a journey。〃
CHAPTER XIV。
THE SCENE SHIFTS。
Having returned the rugs to the Callisto； they applied the
maximum power of the batteries to rising； closed all openings
when the barometer registered thirty； and moved off into space。
When Several thousand miles above the pole； they diverted part of
the power to attracting the nearest moon that was in the plane of
Jupiter's equator； and by the time their upward motion had ceased
were moving well in its direction。 Their rapid motion aided the
work of resisting gravity； since their car had in fact become a
small moon； revolving； like those of Uranus or that of Neptune；
in an orbit varying greatly from the plane of the ecliptic。 As
they flew south at a height ranging from two thousand to three
thousand miles； the planet revolved before them； and they had a
chance of obtaining a thorough view。 There were but a few
scattered islands on the side of the Northern hemisphere opposite
to that over which they had reached the pole； and in the varying
colours of the water； which they attributed to temperature or to
some substance in solution； they recognized what they had always
heard described on earth as the bands of Jupiter； encircling the
planet with great belts； the colour varying with the latitude。
At about latitude forty…five these bands were purple； farther
south light olive green； and at the equator a brown orange。
Shortly after they swung across the equator the ocean again
became purple； and at the same time a well…defined and very
brilliant white spot came into view。 Its brightness showed
slight variations in intensity； though its general shape remained
unchanged。 It had another peculiarity； in that it possessed a
fairly rapid motion of its own； as it moved eastward across the
surface of the ocean。 It exhibited all the phenomena of the
storm they had watched in crossing Secretary Deepwaters Bay； but
covered a larger area； and was far more violent。 Their glasses
showed them vast sheets of spray driven along at tremendous
speed； while the surface was milky white。
〃This；〃 said Bearwarden； picking up a book； 〃solves to my mind
the mystery of the white spot described by the English writer
Chambers； in 1889； as follows：
〃'During the last few years a brilliant white spot has been
visible on the equatorial border of the great southern belt。 A
curious fact in connection with this spot is； that it moves with
a velocity of some two hundred and sixty miles per hour greater
than the red spot。 Denning obtained one hundred and sixty…nine
observations of this bright marking during the years 1880…1883；
and determined the period as nine hours； fifty minutes； eight and
seven tenths seconds （five and a half minutes less than that of
the red spot）。 Although the latter is now somewhat faint； the
white spot gives promise of remaining visible for many years。
During the year 1886 a large number of observations of Jupiter
were made at the Dearborn Observatory； Chicago； U。 S。； by Prof。
G。 W。 Hough； using the eighteen…and…a…half…inch refractor of the
observatory。 Inasmuch as these observations are not only of high
intrinsic interest； but are in conflict； to some extent； with
previous records； a somewhat full abstract of them will be
useful： The object of general interest was the great red spot。
The outline； shape； and size of this remarkable object has
remained without material change from the year 1879； when it was
first observed here； until the present time。 According to our
observations； during the whole of this period it has shown a
sharp and well…defined outline； and at no time has it coalesced
or been joined to any belt in its proximity； as has been alleged
by some observers。 During the year 1885 the middle of the spot
was very much paler in colour than the margins； causing it to
appear as an elliptical ring。 The ring form has continued up to
the present time。 While the outline of the spot has remained
very constant； the colour has changed materially from year to
year。 During the past three years （1884… '86） it has at times
been very faint； so as barely to be visible。 The persistence of
this object for so many years leads me to infer that the formerly
accepted theory； that the phenomena seen on the surface of the
planet are atmospheric； is no longer tenable。 The statement so
often made in text…books； that in the course of a few days or
months the whole aspect of the planet may be changed； is
obviously erroneous。 The oval white spots on the southern
hemisphere of the planet； nine degrees south of the equator； have
been systematically observed at every opposition during the past
eight years。 They are generally found in groups of three or
more； but are rather difficult to observe。 The rotation period
deduced from them is nearly the same as from the great red spot。
These spots usually have a slow drift in longitude of about five
seconds daily in the direction of the planet's rotation； when
referred to the great red spot； corresponding to a rotation
period of twenty seconds less than the latter。'
〃This shows；〃 continued Bearwarden； 〃that as long ago as towards
the close of the nineteenth century the old idea that we saw
nothing but the clouds in Jupiter's atmosphere was beginning to
change； and also how closely the two English writers and Prof。
Hough were studying the subject； though their views did not
entirely agree。 A white spot is merely a storm…centre passing
round and round the planet； the wind running a little ahead of
the surface； which accounts for its rapid rotation compared with
the red spot； which is a fixture。 A critic may say we have no
such winds on earth； to which I reply； that winds on a planet of
Jupiter's size； with its rate of rotationthough it is
480；000；000 miles from the sun and the internal heat is so near
the surfaceand with land and water arranged as they are； may
and indeed must be very different from those prevailing on earth；
the conditions producing and affecting them being so changed。
Though the storm…centre moves two hundred and sixty miles an
hour； the wind need not blow at that rate。〃
Later they saw several smaller spots drifting eastward； but
concluded that any seaworthy ship might pass safely through them；
for； though they were hurricanes of great violence； the waves
were small。
〃There would be less danger；〃 said Bearwarden； 〃of shipping seas
here than there is on earth； the principal risk to travellers
would be that of being blown from the deck。 On account of the
air's weight in connection with its velocity； this would
necessitate some precaution。〃
The next object of interest was the great red spot。 It proved；
as Cortlandt had predicted； to be a continent； with at that time
no special colour； though they easily recognized it by comparing
its outlines with those of the spot in the map。 Its length； as
they already knew； was twenty…seven thousand miles； and its
breadth about eight thousand miles； so that it contained more
square miles than the entire surface of the earth； land and water
included。
〃It is clear；〃 said Cortlandt； 〃that at some season of Jupiter's
long year a change takes place that affects the colour of the
leavessome drought or prolonged norther； for it is obvious that
that is the simplest explanation。 In like manner we may expect
that at some times more white spots will move across the ocean
than at others。〃
〃On account of the size of these continents and oceans；〃 said
Bearwarden； 〃it is easy to believe that many climatic conditions
may prevail here that can scarcely e
