"A watch of the Wheelton Watch Company!" exclaimed Phil Evans.

Whatever might be the reason, there was no doubt that the day was breaking. Gradually the window became white in the deep darkness of the cell. However, if the dawn appeared sooner than the fortieth parallel permitted, it did not advance with the rapidity peculiar to lower latitudes. This was another observation--of Uncle Prudent's - a new inexplicable phenomenon.

"Couldn't we get up to the window and see where we are?"

"We might," said Uncle Prudent. "Frycollin, get up!"

The Negro arose.

"Put your back against the wall," continued Prudent, "and you, Evans, get on his shoulders while I buttress him up."

"Right!" said Evans.

An instant afterwards his knees were on Frycollin's shoulders, and his eyes were level with the window. The window was not of lenticular glass like those on shipboard, but was a simple flat pane. It was small, and Phil Evans found his range of view was much limited.

"Break the glass," said Prudent, "and perhaps you will be able to see better."

Phil Evans gave it a sharp knock with the handle of his bowie-knife. It gave back a silvery sound, but it did not break.

Another and more violent blow. The same result.

"It is unbreakable glass!" said Evans.

It appeared as though the pane was made of glass toughened on the Siemens system--as after several blows it remained intact.

The light had now increased, and Phil Evans could see for some distance within the radius allowed by the frame.

"What do you see?" asked Uncle Prudent.

"Nothing."

"What? Not any trees?"

"No."

"Not even the top branches?"

"No."

"Then we are not in the clearing?:

"Neither in the clearing nor in the park."

"Don't you see any roofs of houses or monuments?" said Prudent, whose disappointment and anger were increasing rapidly.

"No."

"What! Not a flagstaff, nor a church tower, nor a chimney?"

"Nothing but space."

As he uttered the words the door opened. A man appeared on the threshold. It was Robur.

"Honorable balloonists" he said, in a serious voice, "you are now free to go and come as you like."

"Free!" exclaimed Uncle Prudent.

"Yes--within the limits of the "Albatross!" "

Uncle Prudent and Phil Evans rushed out of their prison. And what did they see?

Four thousand feet below them the face of a country they sought in vain to recognize.

Chapter VII

ON BOARD THE ALBATROSS

"When will man cease to crawl in the depths to live in the azure and quiet of the sky?"

To this question of Camille Flammarion's the answer is easy. It will be when the progress of mechanics has enabled us to solve the problem of aviation. And in a few years--as we can foresee--a more practical utilization of electricity will do much towards that solution.

In 1783, before the Montgolfier brothers had built their fire-balloon, and Charles, the physician, had devised his first aerostat, a few adventurous spirits had dreamt of the conquest of space by mechanical means. The first inventors did not think of apparatus lighter than air, for that the science of their time did not allow them to imagine. It was to contrivances heavier than air, to flying machines in imitation of the birds, that they trusted to realize aerial locomotion.

This was exactly what had been done by that madman Icarus, the son of Daedalus, whose wings, fixed together with wax, had melted as they approached the sun.

But without going back to mythological times, without dwelling on Archytas of Tarentum, we find, in the works of Dante of Perugia, of Leonardo da Vinci and Guidotti, the idea of machines made to move through the air. Two centuries and a half afterwards inventors began to multiply. In 1742 the Marquis de Bacqueville designed a system of wings, tried it over the Seine, and fell and broke his arm. In 1768 Paucton conceived the idea of an apparatus with two screws, suspensive and propulsive. In 1781 Meerwein, the architect of the Prince of Baden, built an orthopteric machine, and protested against the tendency of the aerostats which had just been invented.