In a case like this, we can't rely on uncertainties.

Therefore, to make sure of not losing our thermometer, we shall fasten it with a string and easily pull it in whenever we like." This advice being adopted, the window was opened quickly, and the instrument was thrown out at once by M'Nicholl, who held it fastened by a short stout cord so that it could be pulled in immediately.

The window had hardly been open for longer than a second, yet that second had been enough to admit a terrible icy chill into the interior of the Projectile.
"Ten thousand ice-bergs!" cried Ardan, shivering all over; "it's cold enough to freeze a white bear!" Barbican waited quietly for half an hour; that time he considered quite long enough to enable the instrument to acquire the temperature of the interstellar space.

Then he gave the signal, and it was instantly pulled in.
It took him a few moments to calculate the quantity of mercury that had escaped into the little diaphragm attached to the lower part of the instrument; then he said: "A hundred and forty degrees, centigrade, below zero!" [Illustration: IT'S COLD ENOUGH TO FREEZE A WHITE BEAR.] "Two hundred and twenty degrees, Fahrenheit, below zero!" cried M'Nicholl; "no wonder that we should feel a little chilly!" "Pouillet is right, then," said Barbican, "and Fourier wrong." "Another victory for Sorbonne over the Academy!" cried Ardan.

"_Vive la Sorbonne!_ Not that I'm a bit proud of finding myself in the midst of a temperature so very _distingue_--though it is more than three times colder than Hayes ever felt it at Humboldt Glacier or Nevenoff at Yakoutsk.