they all ran to the port holes, which were openings in the side of the ship. they were fitted with thick, double glass, and covered on the outside with steel shutters. these shutters were worked by a single lever from the engine room, so that one person could open or close them in a second or two. washington, by accident, it appeared later, had slid back the protecting pieces of steel, and the rest followed.

as the adventurers looked from the glass ports they saw that the light which had flooded the ship came from without. they were in the midst of a beautiful glow, which seemed to be diffused about them like rays from a sun.

only, in place of being a yellow or white light, such as the sun gives off at varying times, the glow was of violet hue. and, as they watched, they saw the light change color, becoming a beautiful red, then blue, and again green.

“well, this is certainly remarkable!” the professor said. “i wonder what causes that.”

“we’ve arrived! we’re here, anyhow!” washington cried, coming into the room. “see the country!”

then, for the first time, the travelers, taking their attention from the curious light that was all around them, saw that they had indeed arrived. they were on a vast plain, one, seemingly, boundless in extent, though off to the left there was a range of lofty mountains, while to the right there was the glimmer of what might be a big lake or inland sea.

“see, we are resting on the ground!” exclaimed jack. he pointed out of the window, and the others, looking close at hand, noted that the mermaid had settled down in the midst of what seemed to be a field of flowers. big red and yellow blossoms were all in front, and some grew so tall as to almost be up to the edge of the port.

“i wonder if we can be seeing aright,” the professor muttered. “is this really the interior of the earth; such a beautiful place as this?”

there could be little doubt of it. the ship had descended through the big shaft, had been sucked down by the terrible air current, and had really landed in a strange country.

of its size, shape and general conditions the adventurers, as yet, could but guess. they could see it was a pleasant place, and one where there might be the means to sustain life. for, as the professor said afterward, he felt that where there were flowers there would be fruits, and where both of these provisions of nature were to be found there would likely be animal life, and even, perhaps, human beings.

but, for the time, they were content to look from the port on the beautiful scene that lay stretched out before them. the ship rested on an even keel and had landed so softly that none of the plates were strained.

“we have plenty of air, at all events,” said the professor as he took a deep breath. “i was afraid of that, but it seems there was no need. the air appears to be as good and fresh as that on the surface of the earth, only there is a curious property to it. it makes one feel larger. i imagine it must be thinner than the air of the earth, which is a rather strange thing, since the higher one goes the more rarefied the air becomes, and the lower, the more dense. still we can not apply natural philosophy to conditions under the earth. all the usual theories may be upset. however, we should be content to take things as we find them, and be glad we were not dashed to pieces when the ship was caught in the terrible current.”

“what do you suppose caused the awful heat, and then made it go away again?” asked jack.

“i can only make a guess at it,” mr. henderson answered. “there are many strange things we will come across if we stay here long, i believe. as for the fire i think we must have passed a sort of interior volcano.”

“but what sort of a place do you think we have come to, professor?” asked mark.

“it is hard to say,” the scientist replied. “we are certainly somewhere within the earth. our gage tells us it is five hundred miles. that may or may not be correct, but i believe we are several hundred miles under the crust, at all events. as to what sort of a place it is, you can see for yourselves.”

“but how is it we can breathe here, and things can grow?” asked bill, who was beginning to lose his fright at the thought of being practically buried alive.

“i do not know what makes such things possible,” mr. henderson replied, “but that there is air here is a certainty. i can hardly believe it is drawn from the surface of the earth, down the big hole, and i am inclined to think this place of the under-world has an atmosphere of its own, and one which produces different effects than does our own.”

“they certainly have larger flowers than we have,” said mark. “see how big they grow, and what strong colors they have.”

he pointed to the port, against which some of the blooms were nodding in the wind that had sprung up, for, in spite of the many differences, the under-world was in some respects like the upper one.

“probably the difference in the atmosphere accounts for that,” the professor said. “it enables things to grow larger. and, by the way, mark, that reminds me of something you said about seeing some horrible monster fleeing from the ship. did you dream that?”

“i did see something horrible, professor,” he answered. “i’m not positive what it was, but i’ll tell you as nearly as i can what it was like.”

thereupon mark detailed what he had seen.

“but how could anything, least of all some big monster, be concealed in the storeroom, and we not know anything about it?” asked mr. henderson.

“i thought you did know something of it,” replied mark.

“who, me? my dear boy, you must be dreaming again. why should i want to conceal any being in the storeroom? come, there is something back of this. tell me all you know of it. i can’t imagine why you think i was hiding something in the apartment.”

“i thought so because you were always so anxious not to have me go near it,” answered the boy. “don’t you remember when you saw me going toward it, several times, you warned me away?”

“so i did!” exclaimed mr. henderson, a light breaking over his face. “but, mark, it was not because i had hidden some human being or animal there. i can’t tell you what it is yet, save that i can say it is merely a machine of mine that i have invented. for reasons of my own i don’t want any one to see it yet. perhaps it may never be seen. i thought, not long ago, that we might have to undertake a terrible risk in escaping from this place. i directed you to go to the storeroom—but there, i can’t say any more, my friends. sufficient that i had nothing in the animal line concealed there.”

“but i am certain there was some beast or human being in there,” insisted mark. “i heard curious noises in there. besides, how do you account for the food disappearing and the door being open at times?”

“it might have been rats,” said jack.

“i don’t believe there are rats in the ship,” put in the professor. “more likely it was one of us who got up hungry and took the victuals.”

“i’m sorry i can’t agree with you,” mark added respectfully. “i am sure some strange being was on board this ship, and i believe it has now escaped. who or what it was i can’t say, but you’ll find i’m right, some day.”

“all right,” spoke mr. henderson with a laugh. “i like to see any one brave enough to stick up for his opinion, but, at the same time, i can’t very well imagine any person or thing being concealed in that storeroom ever since we started. how could it get in?”

mark did not answer, but there came to him the recollection of that night, previous to the sailing of the flying mermaid, when he had observed some strange shadow that seemed to glide aboard the craft.

“now let’s forget all about such things,” the professor went on. “we are in a strange country, and there are many things to see and do. let’s explore a little. then we must see what we can do with the ship. we are dependent on it, and it will not do to allow it to remain in a damaged state. we expect to travel many miles in the interior of the earth if it is possible, and we have only our craft to go in.”

“i reckon we’d all better assimilate into our interior progression some molecules and atoms of partly disentegrated matter in order to supply combustion for the carbonaceous elements and assist in the manufacture of red corpuscles,” said washington, appearing in the door, with a broad grin on his good-natured face.

“which, being interpreted,” the professor said, “means, i suppose, that we had better eat something to keep our digestive apparatus in good working order?”

“yo’ done guessed it!” exclaimed the colored man, relapsing into his ordinary speech. “i’se got a meal all ready.”

they agreed that they might not have another opportunity soon to partake of food, so they all gathered about the table, on which washington had spread a good meal.

“come on, let’s go outside and view this new and strange land at closer quarters,” the professor said, when they had satisfied their appetites. “we can’t see much from inside the ship.”

accordingly the heavy door in the side of the mermaid was slid back, and, for the first time the travelers stepped out on the surface of the land in the interior of the earth.

at first it seemed no different than the ordinary land to which they were accustomed. but they soon found it had many strange attributes. the queer shifting and changing light, with the myriad of hues was one of them, but to this the adventurers had, by this time, become accustomed, though it was, none the less, a marvel to them. it was odd enough to see the landscape blood red one instant, and a pale green the next, as it does when you look through differently colored glasses.

then, too, they noticed that the grass and flowers grew much more abundantly than in the outer part of the world. they saw clover six feet high, and blades of grass even taller. in some places the growth of grass was so big that they were in danger of getting lost in it.

“if the grass is like this, what will the trees be?” asked mark.

“there are some away over there,” jack replied. “we’ll have to take a sail over. they must be several hundred feet high.”

“well, at any rate, here’s a little brook, and the water looks good to drink,” went on mark. “i’m thirsty, so here goes.”

he hurried to where a stream was flowing sluggishly between grassy banks. the water was as clear as crystal, and mark got down on his face and prepared to sip some of the liquid up.

but, no sooner had his lips touched it, than he sprang up with a cry and stood gazing at the water.

“what’s the matter?” asked jack. “hot?”

“no, it isn’t hot,” mark replied, “but it isn’t water. it’s white molasses!”

“white molasses?” repeated the professor, coming up at that moment. “what are you talking about?”

he stooped down and dipped his finger into the stream. he drew it up quickly, and there ran from it big drops that flowed as slowly as the extract of the sugarcane does in cold weather.

“you’re about right, mark,” he said. “it’s water but it’s almost as thick as molasses.” he touched his finger to his tongue. “it’s good to drink, all right,” he went on, “only it will be a little slow going down.”

then he dipped up a palm full, and let it trickle down his throat.

“it is the strangest water i ever saw,” he added. “it must be that the lack of some peculiar property of air, which we have on the surface, has caused this. i must make some notes on it,” and he drew out pencil and paper. he was about to jot down some facts when he was interrupted by a cry from washington.

“come and see what’s the matter with this stone!” he cried.