. Many of
the streams whose sources they had seen when they crossed the divide
from the lake basin, and whose courses they had followed, were now
rivers a mile wide, with the tide ebbing and rising within them many
hundreds of miles from their mouths. When they reached the shore line
they found the waves breaking, as on earth, upon the sands, but with
this difference: they had before noted the smallness of the undulations
compared with the strength of the wind, the result of the water's
weight. These waves now reminded them of the behaviour of mercury, or
of melted lead when stirred on earth, by the rapidity with which the
crests dropped. Though the wind was blowing an on-shore gale, there
was but little combing, and when there was any it lasted but a second.
The one effort of the crests and waves seemed to be to remain at rest,
or, if stirred in spite of themselves, to subside.

When over the surface of the ocean, the voyagers rose to a height of
thirty thousand metres, and after twenty-four hours' travelling saw, at
a distance of about two hundred miles, what looked like another
continent, but which they knew must be an island. On finding
themselves above it, they rose still higher to obtain a view of its
outlines and compare its shape with that of the islands in the
photographs they had had time to develop. The length ran from
southeast to northwest. Though crossed by latitude forty, and
notwithstanding Jupiter's distance from the sun, the southern side had
a very luxuriant vegetation that was almost semi-tropical. This
they accounted for by its total immunity from cold, the density of the
air at sea-level, and the warm moist breezes it received from the tepid
ocean. The climate was about the same as that of the Riviera or of
Florida in winter, and there was, of course, no parching summer.

"This shows me," said Bearwarden, "that a country's climate depends
less on the amount of heat it receives from the sun than on the amount
it retains; proof of which we have in the tops of the Himalayas
perpetually covered with snow, and snow-capped mountains on the very
equator, where they get the most direct rays, and where those rays have
but little air to penetrate. It shows that the presence of a
substantial atmosphere is as necessary a part of the calculation in
practice as the sun itself. I am inclined to think that, with the
constant effect of the internal heat on its oceans and atmosphere,
Jupiter could