diminished—which is proved by the number of volcanos on the surface of the earth, now actually extinct. And I believe that centuries succeeding to centuries, and insects to insects, this Pacific may one day be changed into a vast continent, which new generations will inhabit and civilize in their turn."
"That will take a long time," said Pencroft.
"Nature has time for it," replied the engineer.
"But what would be the use of new continents?" asked Herbert.
"It appears to me that the present extent of habitable countries is sufficient for humanity. Yet nature does nothing uselessly."
"Nothing uselessly, certainly," replied the engineer, "but this is how the necessity of new continents for the future, and exactly on the tropical zone occupied by the coral islands, may be explained. At least to me this explanation appears plausible."
"We are listening, captain," said Herbert.
"This is my idea; philosophers generally admit that some day our globe will end, or rather that animal and vegetable life will no longer be possible, because of the intense cold to which it will be subjected. What they are not agreed upon, is the cause of this cold. Some think that it will arise from the falling of the temperature, which the sun will experience after millions of years; others, from the gradual extinction of the fires in the interior of our globe, which have a greater influence on it than is generally supposed. I hold to this last hypothesis, grounding it on the fact that the moon is really a cold star, which is no longer habitable, although the sun continues to throw on its surface the same amount of heat. If, then, the moon has become cold, it is because the interior fires are completely extinct. Lastly, whatever may be the cause, our globe will become cold some day, but this cold will only increase gradually. What will happen, then? The temperate zones, at a more or less distant period, will not be more habitable than the polar regions now are. Then the population of men, as well as the animals, will flow towards the latitudes which are more directly under the solar influence. An immense emigration will be performed. Europe, Central Asia, North America, will gradually be abandoned, as well as Australasia and the lower parts of South America. The
