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.