modern terrestrial horse have disappeared； the hoof being in
reality but a rounded…off middle finger。
〃It is wonderful；〃 said Bearwarden； 〃how comparatively narrow
a body of water can keep different species entirely separate。
The island of Sumatra； for instance； is inhabited by marsupials
belonging to the distinct Australian type； in which the female；
as in the kangaroo； carries the slightly developed young in a
pouch； while the Malay peninsula； joined to the mainland； has all
the highly developed animals of Asia and the connected land of
the Eastern hemisphere； the narrow Malacca Strait being all that
has kept marsupials and mammals apart； though the separating
power has been increased by the rapid current setting through。
This has decreased the chance of creatures carried to sea on
drift…wood or uprooted trees getting safely over to such a degree
that apparently none have survived； for； had they done so； we may
be certain that the mammals； with the advantage their young have
over the marsupials； would soon have run them out； the marsupials
being the older and the less perfect form of life of the two。〃
Before leaving the beautiful sea…girt region beneath them；
Cortlandt proposed that it be named after their host； which
Bearwarden seconded； whereupon they entered it as Ayrault Island
on the charts。 After this they rose to a great height； and flew
swiftly over three thousand miles of ocean till they came to
another island not quite as large as the first。 It was four
thousand five hundred miles long by something less than three
thousand wide； and was therefore about the size of Africa。 It
had several high ranges of mountains and a number of great rivers
and fine harbours； while murmuring； bubbling brooks flowed
through its forest glades。 There were active volcanoes along the
northern coast； and the blue； crimson； and purple lines in the
luxuriant foliage were the most beautiful they had ever seen。
〃I propose；〃 said Bearwarden； 〃that we christen this Sylvialand。〃
This Cortlandt immediately seconded； and it was so entered on the
charts。
〃These two islands；〃 said Bearwarden； 〃may become the centres of
civilization。 With flying machines and cables to carry
passengers and information； and ships of great displacement for
the interchange of commodities； there is no limit to their
possible development。 The absence of large waves will also be
very favourable to sea…spiders； which will be able to run at
tremendous speeds。 The constancy in the eruptions of the
volcanoes will offer a great field to Jovian inventors； who will
unquestionably be able to utilize their heat for the production
of steam or electricity； to say nothing of an inexhaustible
supply of valuable chemicals。 They may contain the means of
producing some force entirely different from apergy； and as
superior to electricity as that is to steam。 Our earthly
volcanoes have been put to slight account because of the long
intervals between eruptions。〃
After leaving Sylvialand they went westward to the eastern of the
two crescent continents。 It was separated from the island by
about six thousand miles of ocean； and had less width than the
western； having about the proportions of a three…day crescent；
while the western had the shape of the moon when four or five
days old。 They found the height of the mountains and plateaus
somewhat less than on the eastern continent； but no great
difference in other respects； except that； as they went towards
the pole； the vegetation became more like that of Scotland or a
north temperate region than any they had seen。 On reaching
latitude fifty they again came out over the ocean to investigate
the speckled condition they had observed there。 They found a
vast archipelago covering as great an area as the whole Pacific
Ocean。 The islands varied from the size of Borneo and Madagascar
to that of Sicily and Corsica； while some contained but a few
square miles。 The surface of the archipelago was about equally
divided between land and water。
〃It would take good navigation or an elaborate system of
light…houses；〃 said Bearwarden； 〃for a captain to find the
shortest course through these groups。〃
The islands were covered with shade trees much resembling those
on earth； and the leaves on many were turning yellow and red； for
this hemisphere's autumn had already begun。
〃The Jovian trees；〃 said Cortlandt； 〃can never cease to bear；
though the change of seasons is evidently able to turn their
colour； perhaps by merely ripening them。 When a ripe leaf falls
off； its place is doubtless soon taken by a bud； for germination
and fructification go on side by side。〃
Before leaving； they decided to name this Twentieth Century
Archipelago； since so much of the knowledge appertaining to it
had been acquired in their own day。 At latitude sixty the
northern arms of the two continents came within fifteen hundred
miles of each other。 The eastern extension was split like the
tail of a fish； the great bay formed thereby being filled with
islands； which also extended about half of the distance across。
The western extremity shelved very gradually； the sand…bars
running out for miles just below the surface of the water。
After this the travellers flew northward at great speed in the
upper regions of the air； for they were anxious to hasten their
journey。 They found nothing but unbroken sea； and not till they
reached latitude eighty…seven was there a sign of ice。 They then
saw some small bergs and field ice； but in no great quantities。
As their outside thermometer； when just above the placid
waterfor there were no waves hereregistered twenty… one
degrees Fahrenheit； they accounted for this scarcity of ice by
the absence of land on which fresh water could freeze； and by the
fact that it was not cold enough to congeal the very salt
sea…water。
Finally they reached another archipelago a few hundred miles in
extent； the larger islands of which were covered with a sheet of
ice； at the edges of which small icebergs were being formed by
breaking off and slowly floating。 Finding a small island on
which the coating was thin； they grounded the Callisto； and
stepped out for the first time in several days。 The air was so
still that a small piece of paper released at a height of six
feet sank slowly and went as straight as the string of a
plumb…line。 The sun was bisected by the line of the horizon； and
appeared to be moving about them in a circle； with only its upper
half visible。 As Jupiter's northern hemisphere was passing
through its autumnal equinox； they concluded they had landed
exactly at the pole。
〃Now to work on our experiment；〃 said Cortlandt。 〃I wonder how we
may best get below the frozen surface？〃
〃We can explode a small quantity of dynamite；〃 replied
Bearwarden； 〃after which the digging will be comparatively easy。〃
While Cortlandt and Bearwarden prepared the mine； Ayrault brought
out a pickaxe； two shovels； and the battery and wires with which
to ignite the explosive。 They made their preparations within one
hundred feet of the Callisto； or much nearer than an equivalent
amount of gunpowder could have been discharged。
〃This recalls an old laboratory experiment； or rather lecture；〃
said Cortlandt； as they completed the arrangements； 〃for the
illustration is not as a rule carried out。 Explode two pounds of
powder on an iron safe in a room with the windows closed； and the
windows will be blown out； while the safe remains uninjured。
Explode an equivalent amount of dynamite on top of the safe； and
it will be destroyed； while the glass panes are not even cracked。
This illustrates the difference in rapidity with which the
explosions take place。 To the intensely rapid action of dynamite
the air affords as much resistance as a solid substance； while
the explosion of the powder is so slow that the air has time to
move away； hence the destruction of the windows in the first
case； and the safe in the second。〃
When they had moved beyond the danger line； Bearwarden； as the
party's practising engineer； pressed the button； and the
explosion did the rest。 They found that the ground was frozen to
a depth of but little more than a foot； below which it became
perceptibly warm。 Plying their shovels vigorously； they had soon
dug the hole so deep that its edges were above their heads。 When
the floor was ten feet below the surrounding level the
thermometer registered sixty。
〃This is scarcely a fair test；〃 said Cortlandt； 〃since the heat
rises and is lost as fast as given off。 Let us therefore close
the opening and see in what time it will melt a number of cubic
feet of ice。〃
Accordingly they climbed out； threw in about a cart…load of ice；
and covered the opening with two of the Callisto's thick rugs。
In half an hour all the ice had melted； and in another half hour
the water was hot。
〃No arctic expedition need freeze to death here；〃 said
Bearwarden； 〃since all a man would have to do would be to burrow
a few feet to be as warm as toast。〃
As the island on which they had landed was at one side of the
archipelago； but was itself at the exact pole； it followed that
the centre of the archipelago was not the part farthest north。
This in a measure accounted for the slight thickness of ice and
snow； for the isobaric lines would slope； and consequently what
wind there was would flow towards the interior of the
archipelago； whose surface was colder than the surrounding ocean。
The moist air； however； coming almost entirely from the south；
would lose most of its moisture by condensation in passing over
the ice…laden land； and so； like the clouds over the region east
of the Andes； would have but little left to let fall on this
extreme northern part。 The blanketing effect of a great
thickness of snow would also cause； the lower strata of ice to
melt； by keeping in the heat constantly given off by the warm
planet。
〃I think there can be no question；〃 said Cortlandt； 〃that； as a
result of Jupiter's great flattening at the poles and the drawing
of the crust； which moves faster in Jupiter's rotation than any
other part； towards the equator； the