During this conversation we had been rapidly walking, or I should better say advancing, for we no longer walked as men do, but skipped down into the earth, down, ever downward. There were long periods of silence, in which I was engaged in meditating over the problems that successively demanded solution, and even had I desired to do so I could have kept no record of time; days, or even weeks, may have been consumed in this journey. Neither have I any method of judging of the rapidity of our motion. I was sensible of a marked decrease in the amount of muscular energy required to carry us onward, and I realized that my body was quite exempt from weariness. Motion became restful instead of exhausting, and it seemed to me that the ratio of the loss of weight, as shown by our free movements, in proportion to the distance we traversed, was greater than formerly. The slightest exhibition of propelling force cast us rapidly forward. Instead of the laborious, short step of upper earth, a single leap would carry us many yards. A slight spring, and with our bodies in space, we would skip several rods, alighting gently, to move again as easily. I marveled, for, although I had been led to anticipate something unusual, the practical evidence was wonderfully impressive, and I again questioned my guide.
"We are now nearing what physicists would call the center of gravity," he replied, "and our weight is rapidly diminishing. This is in exact accordance with the laws that govern the force called gravitation, which, at the earth's surface, is apparently uniform, though no instrument known to man can demonstrate its exact variation within the field man occupies. Men have not, as yet, been in a position to estimate this change, although it is known that mountains attract objects, and that a change in weight as we descend into the earth is perceptible; but to evolve the true law, observation, at a distance of at least ten miles beneath the surface of the ocean is necessary, and man, being a creature whose motions are confined to a thin, horizontal skin of earth, has never been one mile beneath its surface, and in consequence his opportunities for comparison are extremely limited."
"I have been taught," I replied, "that the force of gravitation decreases until the center of the earth is reached, at which point a body is without weight; and I can scarcely understand how such positive statements from scientific men can be far from the truth."
"It is supposed by your surface men that the maximum of weight is to be found at one-sixth the distance beneath the surface of the earth, and therefrom decreases until at the center it is nothing at all," he replied. "This hypothesis, though, a stagger toward the right, is far from the truth, but as near as could be expected, when we consider the data upon which men base their calculations. Were it not for the purpose of controverting erroneous views, men would have little incentive to continue their investigations, and as has been the rule in science heretofore, the truth will, in time, appear in this case. One generation of students disproves the accepted theories of that which precedes, all working to eliminate error, all adding factors of error, and all together moving toward a common goal, a grand generalization, that as yet can not be perceived. And still each series of workers is overlooking phenomena that, though obvious, are yet unperceived, but which will make evident to future scientists the mistakes of the present. As an example of the manner in which facts are thus overlooked, in your journey you have been impressed with certain surprising external conditions, or surroundings, and yet are oblivious to conditions more remarkable in your own body. So it is with scientists. They overlook prominent facts that stare them boldly in the face, facts that are so conspicuous as to be invisible by reason of their very nearness."
"This statement I can not disprove, and therefore must admit under protest. Where there is so much that appears mysterious I may have overlooked some things, but I can scarcely accept that, in ignorance, I have passed conditions in my own organization so marked as this decrease in gravity which has so strikingly been called to my attention."
"You have, and to convince you I need only say that you have nearly ceased to breathe, and are unconscious of the fact."
I stopped short, in momentary alarm, and now that my mind was directed to the fact, I became aware that I did not desire to breathe, and that my chest had ceased to heave with the alternate inhalation and exhalation of former times. I closed my lips firmly, and for a long period there was no desire for breath, then a slight involuntary inhalation followed, and an exhalation, scarcely noticeable, succeeded by a great interval of inaction. I impulsively turned my face toward the passage we had trod; a feeling of alarm possessed me, an uncontrollable, inexpressible desire to flee from the mysterious earth-being beside me, to return to men, and be an earth-surface man again, and I started backward through the chamber we had passed.
The guide seized me by the hand, "Hold, hold," he cried; "where would you go, fickle mortal?"
"To the surface," I shouted; "to daylight again. Unhand me, unearthly creature, abnormal being, man or devil; have you not inveigled me far enough into occult realms that should be forever sealed from mankind? Have you not taken from me all that men love or cherish, and undone every tie of kith or kin? Have you not led me into paths that the imagination of the novelist dare not conjure, and into experiences that pen in human hand would not venture to describe as possible, until I now stand with my feet on the boundary line that borders vacancy, and utter loss of weight; with a body nearly lost as a material substance, verging into nothing, and lastly with breath practically extinguished, I say, and repeat, is it not time that I should hesitate and pause in my reckless career?"
"It is not time," he answered.
"When will that hour come?" I asked in desperation, and I trembled as he replied:
"When the three Great Lights are closed."