its way. With what a soft sweet light every star glowed! No matter what its magnitude, the stream that flowed from it looked calm and holy. No twinkling, no scintillation, no nictitation, disturbed their pure and lambent gleam. No atmosphere here interposed its layers of humidity or of unequal density to interrupt the stately majesty of their effulgence. The longer he gazed upon them, the more absorbing became their attraction. He felt that they were great kindly eyes looking down even yet with benevolence and protection on himself and his companions now driving wildly through space, and lost in the pathless depths of the black ocean of infinity!
He soon became aware that his friends, following his example, had interested themselves in gazing at the stars, and were now just as absorbed as himself in the contemplation of the transcendent spectacle. For a long time all three continued to feast their eyes on all the glories of the starry firmament; but, strange to say, the part that seemed to possess the strangest and weirdest fascination for their wandering glances was the spot where the vast disc of the Moon showed like an enormous round hole, black and soundless, and apparently deep enough to permit a glance into the darkest mysteries of the infinite.
A disagreeable sensation, however, against which they had been for some time struggling, at last put an end to their contemplations, and compelled them to think of themselves. This was nothing less than a pretty sharp cold, at first somewhat endurable, but which soon covered the inside surface of the window panes with a thick coating of ice. The fact was that, the Sun's direct rays having no longer an opportunity of warming up the Projectile, the latter began to lose rapidly by radiation whatever heat it had stored away within its walls. The consequence was a very decided falling of the thermometer, and so thick a condensation of the internal moisture on the window glasses as to soon render all external observations extremely difficult, if not actually impossible.
The Captain, as the oldest man in the party, claimed the privilege of saying he could stand it no longer. Striking a light, he consulted the thermometer and cried out:
"Seventeen degrees below zero, centigrade! that is certainly low enough to make an old fellow like me feel rather chilly!"
"Just one degree and a half above zero, Fahrenheit!" observed Barbican; "I really had no idea that it was so cold."
His teeth actually chattered so much that he could hardly articulate; still he, as well as the others, disliked to entrench on their short supply of gas.
"One feature of our journey that I particularly admire," said Ardan, trying to laugh with freezing lips, "is that we can't complain of monotony. At one time we are frying with the heat and blinded with the light, like Indians caught on a burning prairie; at another, we are freezing in the pitchy darkness of a hyperborean winter, like Sir John Franklin's merry men in the Bay of Boothia. Madame La Nature, you don't forget your devotees; on the contrary, you overwhelm us with your attentions!"
"Our external temperature may be reckoned at how much?" asked the Captain, making a desperate effort to keep up the conversation.
"The temperature outside our Projectile must be precisely the same as that of interstellar space in general," answered Barbican.
"Is not this precisely the moment then," interposed Ardan, quickly, "for making an experiment which we could never have made as long as we were in the sunshine?"
"That's so!" exclaimed Barbican; "now or never! I'm glad you thought of it, Ardan. We are just now in the position to find out the temperature of space by actual experiment, and so see whose calculations are right, Fourier's or Pouillet's."
"Let's see," asked Ardan, "who was Fourier, and who was Pouillet?"
"Baron Fourier, of the French Academy, wrote a famous treatise on Heat, which I remember reading twenty years ago in Penington's book store," promptly responded the Captain; "Pouillet was an eminent professor of Physics at the Sorbonne, where he died, last year, I think."
"Thank you, Captain," said Ardan; "the cold does not injure your memory, though it is decidedly on the advance. See how thick the ice is already on the window panes! Let it only keep on and we shall soon have our breaths falling around us in flakes of snow."
"Let us prepare a thermometer," said Barbican, who had already set himself to work in a business-like manner.
A thermometer of the usual kind, as may be readily supposed, would be of no use whatever in the experiment that was now about to be made. In an ordinary thermometer Mercury freezes hard when exposed to a temperature of 40° below zero. But Barbican had provided himself with a Minimum, self-recording thermometer, of a peculiar nature, invented by Wolferdin, a friend of Arago's, which could correctly register exceedingly low degrees of temperature. Before beginning the experiment, this instrument was tested by comparison with one of the usual kind, and then Barbican hesitated a few moments regarding the best means of employing it.
"How shall we start this experiment?" asked the Captain.
"Nothing simpler," answered Ardan, always ready to reply; "you just open your windows, and fling out your thermometer. It follows your Projectile, as a calf follows her mother. In a quarter of an hour you put out your hand—"
"Put out your hand!" interrupted Barbican.
"Put out your hand—" continued Ardan, quietly.
"You do nothing of the kind," again interrupted Barbican; "that is, unless you prefer, instead of a hand, to pull back a frozen stump, shapeless, colorless and lifeless!"
"I prefer a hand," said Ardan, surprised and interested.
"Yes," continued Barbican, "the instant your hand left the Projectile, it would experience the same terrible sensations as is produced by cauterizing it with an iron bar white hot. For heat, whether rushing rapidly out of our bodies or rapidly entering them, is identically the same force and does the same amount of damage. Besides I am by no means certain that we are still followed by the objects that we flung out of the Projectile."
"Why not?" asked M'Nicholl; "we saw them all outside not long ago."
"But we can't see them outside now," answered Barbican; "that may be accounted for, I know, by the darkness, but it may be also by the fact of their not being there at all. 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!"
"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
