"Well, my owii opinion is that my head is not ex- actly right. In fact, I believe myself slightly de- lirious." "What makes you think so?" "I will explain why I fancy I have lost my senses," I cried. "Have we not returned to the surface of mother earth?" "Certainly not." "Then truly 1 must be mad, for do I not see the light of day? do 1 not hear the whistling of the wind? and can I not distinguish the wash of a great sea?" "And that is ail that makes you uneasy?" said- ray uncle, with a smile. "Can you explain?" "I win not make any attempt to explain; for the whole matter is utterly inexplicable. But you shall see and judge for yourself. You will then find that' geological science is as yet in its infancy — and that We are doomed to enlighten the world." "Let us advance, then," I cried eagerly, no longer able to restrain my eurioaity. "Wait a moment, my dear Harry," he responded; "you must take precautions after your illness be- faore going into the open air." "The open air?" "Yea, my boy. I have to warn you that the wind is rather violent — and I have no wish for you to ex- pose yourself without necessary precautions." "But I beg to assure you that I am perfectly re- covered from ray illness." "Have just a little patience, my boy. A relapse would be inconvenient to all parties. We have no time to lose— as our approaching sea voyage may be of long duration." "Sea voyage?" I cried, more bewildered than ever. "Yes, You must take another day's rest, and we shall be ready to go on board fay to-morroWf'y'e- ' plied my uncle, with a peculiar smile. „ ■ Go on board! The words utterly astonished me Go on board — what? and how? Had we come mqn a river, a lake, had we discovered some inland 30^? Was a vesseliyiog at anchor in some'^i't of the interior of the earth? Q^ My curiosity was worked up to^the very highest pitch. IVIy uncle made vain attempts to restrain me. When at last, however, he discovered that my fever- ish impatience would do more harm than goq^-r and that the satisfaction of my wishes couldmone restore me to a calm state of mind, he gave way. I dressed myself rapidly — and then to please my uncle, taking the precaution of wrapping myself in one of the coverlets, I rushed out of the grotto. CHAPTER XXVII The Central Sea AT first I saw absolutely nothing. My eyes, wholly unused to the effulgence of light, could not bear the sudden brightness; and I was compelled to close them. When I was able to re-open them, I stood still, far more stupefied than aston- ished. Not all the wildest effects of imagination could have conjured up such a scene! "The sea-^ the sea," I cried. "Yes," replied my uncle, in a tone of pardonable pride; "The Centr^ Sea, No future navigator will deny the fact of my having discovered it; and hence of acquiring a right of giving it a name," It was (luite true, A vast, limitless expanse of water, the end of a lake if not of an ocean, spread before us, until it was lost in the distance. The shore, which was very much indented, consisted of a beautiful soft golden sand, mixed with small shells, the long deserted homes of some of the crea- tures of a past age. The waves broke incessantly, and with a peculiarly sonorous murmur — to be found in underground localities. A alight frothy flake ai'ose as the wind blew along the pellucid waters; and many a dash of spray was blown into my face. The mighty superstructure of rock which rose above to an inconceivable height, left only a narrow margin — but , where we stood, there was a long beach of strand. On all sides were capes and promontories and enormous cliffs, partially worn by the eternal breaking of the waves, through countless ages! And as I gazed from side to side, the mighty rocks faded In the distance like a fleecy iilm of cioud. It was in reality an ocean, with all the usual characteristics of an inland sea, only horribly wild — so rigid, cold and savage. One thing startled and puzzled me greatly. How was it that I was able to look upon that vast sheet •of water instead of being plunged in utter dark- ness? The vast landscape before me was lit up like day. But there was wanting the dazzling brilliancy, the splendid irradiation of the- sun; the pale cold illumination of the moon; the brightness of the stars. The illuminating power in this subterraneous region, from its trembling and flickering character, its clear dry whiteness, the very slight elevation of its^emperature, its great superiority to that of the mpoh, was evidently electric; something in the na- .ture of the aurora borealis, only that its phenomena V^ere constant, and able to light up the whole of the ocean cavern. The tremendous vault above our heads, the sky, so to speak, appeared to be composed of a conglom- eration of nebulous vapors, in constant motion. I should originally have supposed, that under such an atmospheric pressure as must exist in that place, the evaporation of water could not really take place; yet there were heavy and dense clouds rolling along that mighty vault, partially concealing the roof. Electric currents produced astonishing play of light and shade in the distance, especially around the heavier clouds. Deep shadows were cast beneath^ and then suddenly, between two clouds, there would come a ray of unusual beauty, and remarkable in- tensity. Yet it was not like the sun, for it gave no heat. The effect was sad and excruciatingly melancholy. Instead of a noble firmament of blue, studded with stars, there was above me a heavy roof of granite, which seemed to crush me. Gazing around, I began to think of the theory of the English captain, vd'.o compared the earth to a vast hollow sphere in the interior of which the air is retained in a luminous state by means of atmospheric pressure, while two stars'; Pluto and Proserpine, circle there in their mysterious orbits. After all, suppose the old fellow was right! In truth, we were imprisoned — bound as it were, in a vast excavation. Its width it waa impossible to