"What," I cried, rising in astonishment, "did you say, the tide, uncle?"
"Certainly I did."
"You do not mean to say," I replied, in a tone of respectful doubt, "that the influence of the sun and moon is felt here below."
"And pray why not? Are not all bodies influenced by the law of universal attraction? Why should this vast underground sea be exempt from the general law, the rule of the universe? Besides, there is nothing like that which is proved and demonstrated. Despite the great atmospheric pressure down here, you will notice that this inland sea rises and falls with as much regularity as the Atlantic itself."
As my uncle spoke, we reached the sandy shore, and saw and heard the waves breaking monotonously on the beach. They were evidently rising.
"This is truly the flood," I cried, looking at the water at my feet.
"Yes, my excellent nephew," replied my uncle, rubbing his hands with the gusto of a philosopher, "and you see by these several streaks of foam, that the tide rises at least ten or twelve feet."
"It is indeed marvelous."
"By no means," he responded; "on the contrary, it is quite natural."
"It may appear so in your eyes, my dear uncle," was my reply, "but the whole group of phenomena of the place appear to me to partake of the marvelous. It is almost impossible to believe that which I see. Who in his wildest dreams could have imagined that, beneath the crust of our earth, there could exist a real ocean, with ebbing and flowing tides, with its changes of winds, and even its storms. I for one should have laughed the suggestion to scorn."
"But, Harry, my boy, why not?" inquired my uncle, with a pitying smile, "is there any physical reason in opposition to it?"
"Not if we give up the great theory of the central heat of the earth. That point once granted, I certainly can see no reason for doubting the existence of seas and other wonders, even countries, in the interior of the globe."
"That is so—but of course these varied countries are uninhabited?"
"Well, I grant that it is more likely than not; still, I do not see why this sea should not have given shelter to some species of unknown fish."
"Hitherto we have not discovered any, and the probabilities are rather against our ever doing so," observed the Professor.
I was losing my skepticism in the presence of these wonders. "Well, I am determined to solve the question. It is my intention to try my luck with my fishing line and hook."
"Certainly; make the experiment," said my uncle, pleased with my enthusiasm. "While we are about it, it will certainly be only proper to discover all the secrets of this extraordinary region.
"But, after all, where are we now?" I asked; "all this time I have quite forgotten to ask you a question, which, doubtless, your philosophical instruments have long since answered."
"Well," replied the Professor, "examining the situation from only one point of view, we are now distant three hundred and fifty leagues from Iceland."
"So much?" was my exclamation.
"I have gone over the matter several times, and am sure not to have made a mistake of five hundred yards," replied my uncle positively.
"And as to the direction—are we still going to the southeast?"
"Yes, with a western declination of nineteen degrees, forty-two minutes, just as it is above. As for the inclination I have discovered a very curious fact."
"What may that be, uncle? Your information interests me."
"Why that the needle, instead of dipping towards the pole as it does on earth, in the northern hemisphere, has an upward tendency."
"This proves," I cried, "that the great point of magnetic attraction lies somewhere between the surface of the earth and the spot we have succeeded in reaching."
"Exactly, my observant nephew," exclaimed my uncle, elated and delighted, "and it is quite probable that if we succeed in getting toward the polar regions—somewhere near the seventy-third degree of latitude, where Sir James Ross discovered the magnetic pole, we shall behold the needle point directly upward. We have therefore discovered that this great center of attraction is not situation at a very great depth."
"Well," said I, rather surprised, "this discovery will astonish experimental philosophers. It was never suspected."
"Science, great, mighty and in the end unerring," replied my uncle dogmatically, "science has fallen into many errors—errors which have been fortunate and useful rather that otherwise, for they have been the stepping-stones to truth."
After some further discussion, I turned to another matter. "Have you any idea of the depth we have reached?"
"We are now," continued the Professor, "exactly thirty-five leagues—above a hundred miles—down into the interior of the earth."
"So," said I, after measuring the distance on the map, "we are now beneath the Scottish Highlands, and have over our heads the lofty Grampian hills."
"You are quite right," said the Professor laughing, "it sounds very alarming, the weight being heavy—but the vault which supports this vast mass of earth and rock is solid and safe—the mighty Architect of the Universe has constructed it of solid materials. Man, even in his highest flights of vivid and poetic imagination, never thought of such things! What are the finest arches of our bridges, what the vaulted roofs of our cathedrals, to that mighty dome above us, and beneath which floats an ocean with its storms and calms and tides!"
"I admire it all as much as you can, uncle, and have no fear that our granite sky will fall upon our heads. But now that we have discussed matters of science and discovery, what are your future intentions? Are you not thinking of getting back to the surface of our beautiful earth?" This was said more as a feeler than with any hope of success.
"Go back, nephew," cried my uncle in a tone of
