His words recalled them at once to a full sense of their situation.
"Moving?
Blessed if I can tell!" said Ardan, still speaking French.
"We may be lying fifty feet deep in a Florida marsh, for all I know," observed M'Nicholl.
"Or, likely as not, in the bottom of the Gulf of Mexico," suggested Ardan, still in French.
"Suppose we find out," observed Barbican, jumping up to try, his voice as clear and his step as firm as ever.
But trying is one thing, and finding out another.

Having no means of comparing themselves with external objects, they could not possibly tell whether they were moving, or at an absolute stand-still.

Though our Earth is whirling us continually around the Sun at the tremendous speed of 500 miles a minute, its inhabitants are totally unconscious of the slightest motion.

It was the same with our travellers.

Through their own personal consciousness they could tell absolutely nothing.