Imagination loses itself in this sublime Infinity, amid which the projectile was gravitating, like a new star created by the hand of man. From a natural cause, these constellations shone with a soft luster; they did not twinkle, for there was no atmosphere which, by the intervention of its layers unequally dense and of different degrees of humidity, produces this scintillation. These stars were soft eyes, looking out into the dark night, amid the silence of absolute space.
Long did the travelers stand mute, watching the constellated firmament, upon which the moon, like a vast screen, made an enormous black hole. But at length a painful sensation drew them from their watchings. This was an intense cold, which soon covered the inside of the glass of the scuttles with a thick coating of ice. The sun was no longer warming the projectile with its direct rays, and thus it was losing the heat stored up in its walls by degrees. This heat was rapidly evaporating into space by radiation, and a considerably lower temperature was the result. The humidity of the interior was changed into ice upon contact with the glass, preventing all observation.
Nicholl consulted the thermometer, and saw that it had fallen to seventeen degrees (Centigrade) below zero. [3] So that, in spite of the many reasons for economizing, Barbicane, after having begged light from the gas, was also obliged to beg for heat.
The projectile's low temperature was no longer endurable.
Its tenants would have been frozen to death.
[3] 1@ Fahrenheit.
"Well!" observed Michel, "we cannot reasonably complain of the monotony of our journey! What variety we have had, at least in temperature. Now we are blinded with light and saturated with heat, like the Indians of the Pampas! now plunged into profound darkness, amid the cold, like the Esquimaux of the north pole.
No, indeed! we have no right to complain; nature does wonders in our honor.""But," asked Nicholl, "what is the temperature outside?""Exactly that of the planetary space," replied Barbicane.
"Then," continued Michel Ardan, "would not this be the time to make the experiment which we dared not attempt when we were drowned in the sun's rays?
"It is now or never," replied Barbicane, "for we are in a good position to verify the temperature of space, and see if Fourier or Pouillet's calculations are exact.""In any case it is cold," said Michel. "See! the steam of the interior is condensing on the glasses of the scuttles. If the fall continues, the vapor of our breath will fall in snow around us.""Let us prepare a thermometer," said Barbicane.
We may imagine that an ordinary thermometer would afford no result under the circumstances in which this instrument was to be exposed. The mercury would have been frozen in its ball, as below 42@ Fahrenheit below zero it is no longer liquid.
But Barbicane had furnished himself with a spirit thermometer on Wafferdin's system, which gives the minima of excessively low temperatures.
Before beginning the experiment, this instrument was compared with an ordinary one, and then Barbicane prepared to use it.
"How shall we set about it?" asked Nicholl.
"Nothing is easier," replied Michel Ardan, who was never at a loss.
"We open the scuttle rapidly; throw out the instrument; it follows the projectile with exemplary docility; and a quarter of an hour after, draw it in.""With the hand?" asked Barbicane.
"With the hand," replied Michel.
"Well, then, my friend, do not expose yourself," answered Barbicane, "for the hand that you draw in again will be nothing but a stump frozen and deformed by the frightful cold.""Really!"
"You will feel as if you had had a terrible burn, like that of iron at a white heat; for whether the heat leaves our bodies briskly or enters briskly, it is exactly the same thing.
Besides, I am not at all certain that the objects we have thrown out are still following us.""Why not?" asked Nicholl.
"Because, if we are passing through an atmosphere of the slightest density, these objects will be retarded. Again, the darkness prevents our seeing if they still float around us.
But in order not to expose ourselves to the loss of our thermometer, we will fasten it, and we can then more easily pull it back again."Barbicane's advice was followed. Through the scuttle rapidly opened, Nicholl threw out the instrument, which was held by a short cord, so that it might be more easily drawn up. The scuttle had not been opened more than a second, but that second had sufficed to let in a most intense cold.
"The devil!" exclaimed Michel Ardan, "it is cold enough to freeze a white bear."Barbicane waited until half an hour had elapsed, which was more than time enough to allow the instrument to fall to the level of the surrounding temperature. Then it was rapidly pulled in.
Barbicane calculated the quantity of spirits of wine overflowed into the little vial soldered to the lower part of the instrument, and said:
"A hundred and forty degrees Centigrade [4] below zero!"[4] 218 degrees Fahrenheit below zero.
M. Pouillet was right and Fourier wrong. That was the undoubted temperature of the starry space. Such is, perhaps, that of the lunar continents, when the orb of night has lost by radiation all the heat which fifteen days of sun have poured into her.