grees?"

"Yes," answered the doctor; "a thermometer exposed to the open air and
sheltered from reflection has never risen above 135 degrees, and in
the greatest colds it never falls below -72 degrees. So, my friends,
you see we can take our ease."

"But still," said Johnson, "if the sun were to be extinguished
suddenly, would not the earth endure greater cold?"

"The sun won't be extinguished," answered the doctor; "but even if it
should be, the temperature would not fall any lower, probably, than
what I have mentioned."

"That's strange."

"O, I know it used to be said that in the space outside of the
atmosphere the temperature was thousands of degrees below zero! but
since the experiments of the Frenchman Fourrier, this has been
disproved; he has shown that if the earth were placed in a medium void
of all heat, that the temperature at the pole would be much greater,
and that there would be very great differences between night and day;
so, my friends, it is no colder a few millions of miles from the earth
than it is here."

"Tell me, Doctor," said Altamont, "is not the temperature of America
lower than that of other countries of the world?"

"Without doubt; but don't be proud of it," answered the doctor with a
laugh.

"And what is the reason?"

"No very satisfactory explanation has ever been given; so it occurred
to Hadley that a comet had come into collision with the earth and had
altered the position of its axis of rotation, that is to say, of its
poles; according to him, the North Pole, which used to be situated at
Hudson's Bay, found itself carried farther east, and the land at the
old Pole preserved a greater cold, which long centuries of the sun
have not yet heated."

"And you do not admit this hypothesis?"

"Not for a moment; for what is true of the eastern coast of America is
not true of the western coast, which has a higher temperature. No! we
can prove that the isothermal lines differ from the terrestrial
parallels, and that is all."

"Do you know, Doctor," said Johnson, "that it is pleasant to talk
about cold in our present circumstances?"

"Exactly, Johnson; we can call practice to the aid of theory. These
countries are a vast laboratory where curious experiments on low
temperatures can be made. Only, be always careful; if any part of your
body is frozen, rub it at once with snow to restore the circulation of
the blood; and if you come near the fire, be careful, for you may burn
your hand