his answer after a few moments.

..........

"It is of the utmost consequence that we should know how far we are
asunder."

..........

"That is not difficult."

..........

"You have your chronometer at hand?" I asked.

..........

"Certainly."

..........

"Well, take it into your hand. Pronounce my name, noting exactly the
second at which you speak. I will reply as soon as I hear your
words--and you will then note exactly the moment at which my reply
reaches you."

..........

"Very good; and the mean time between my question and your answer will
be the time occupied by my voice in reaching you."

..........

"That is exactly what I mean, Uncle," was my eager reply.

..........

"Are you ready?"

..........

"Yes."

..........

"Well, make ready, I am about to pronounce your name," said the
Professor.

I applied my ear close to the sides of the cavernous gallery, and as
soon as the word "Harry" reached my ear, I turned round and, placing my
lips to the wall, repeated the sound.

..........

"Forty seconds," said my uncle. "There has elapsed forty seconds between
the two words. The sound, therefore, takes twenty seconds to ascend.
Now, allowing a thousand and twenty feet for every second--we have
twenty thousand four hundred feet--a league and a half and one-eighth."

These words fell on my soul like a kind of death knell.

"A league and a half," I muttered in a low and despairing voice.

..........

"It shall be got over, my boy," cried my uncle in a cheery tone; "depend
on us."

..........

"But do you know whether to ascend or descend?" I asked faintly enough.

..........

"We have to descend, and I will tell you why. You have reached a vast
open space, a kind of bare crossroad, from which galleries diverge in
every direction. That in which you are now lying must necessarily bring
you to this point, for it appears that all these mighty fissures, these
fractures of the globe's interior, radiate from the vast cavern which we
at this moment occupy. Rouse yourself, then, have courage and continue
your route. Walk if you can, if not drag yourself along--slide, if
nothing else is possible. The slope must be rather rapid--and you will
find strong arms to receive you at the end of your journey. Make a
start, like a good fellow."

These words served to rouse some kind of courage in my sinking frame.

"Farewell for the present, good uncle, I am about to take my departure.
A