When Jim felt something firm under his feet the poor beast's legs trembled so much that he could hardly stand; but Zeb at once leaped out of the buggy to the roof, and he was so awkward and hasty that he kicked over Dorothy's bird-cage, which rolled out upon the roof so that the bottom came off. At once a pink kitten crept out of the upset cage, sat down upon the glass roof, and yawned and blinked its round eyes.
"Oh," said Dorothy. "There's Eureka."
"First time I ever saw a pink cat," said Zeb.
"Eureka isn't pink; she's white. It's this queer light that gives her that color."
"Where's my milk?" asked the kitten, looking up into Dorothy's face. "I'm 'most starved to death."
"Oh, Eureka! Can you talk?"
"Talk! Am I talking? Good gracious, I believe I am. Isn't it funny?" asked the kitten.
"It's all wrong," said Zeb, gravely. "Animals ought not to talk. But even old Jim has been saying things since we had our accident."
"I can't see that it's wrong," remarked Jim, in his gruff tones. "At least, it isn't as wrong as some other things. What's going to become of us now?"
"I don't know," answered the boy, looking around him curiously.
The houses of the city were all made of glass, so clear and transparent that one could look through the walls as easily as through a window. Dorothy saw, underneath the roof on which she stood, several rooms used for rest chambers, and even thought she could make out a number of queer forms huddled into the corners of these rooms.
The roof beside them had a great hole smashed through it, and pieces of glass were lying scattered in every direction. A nearby steeple had been broken off short and the fragments lay heaped beside it. Other buildings were cracked in places or had corners chipped off from them; but they must have been very beautiful before these accidents had happened to mar their perfection. The rainbow tints from the colored suns fell upon the glass city softly and gave to the buildings many delicate, shifting hues which were very pretty to see.
But not a sound had broken the stillness since the strangers had arrived, except that of their own voices. They began to wonder if there were no people to inhabit this magnificent city of the inner world.
Suddenly a man appeared through a hole in the roof next to the one they were on and stepped into plain view. He was not a very large man, but was well formed and had a beautiful face—calm and serene as the face of a fine portrait. His clothing fitted his form snugly and was gorgeously colored in brilliant shades of green, which varied as the sunbeams touched them but was not wholly influenced by the solar rays.
The man had taken a step or two across the glass roof before he noticed the presence of the strangers; but then he stopped abruptly. There was no expression of either fear or surprise upon his tranquil face, yet he must have been both astonished and afraid; for after his eyes had rested upon the ungainly form of the horse for a moment he walked rapidly to the furthest edge of the roof, his head turned back over his shoulder to gaze at the strange animal.
"Look out!" cried Dorothy, who noticed that the beautiful man did not look where he was going; "be careful, or you'll fall off!"
But he paid no attention to her warning. He reached the edge of the tall roof, stepped one foot out into the air, and walked into space as calmly as if he were on firm ground.
The girl, greatly astonished, ran to lean over the edge of the roof, and saw the man walking rapidly through the air toward the ground. Soon he reached the street and disappeared through a glass doorway into one of the glass buildings.
"How strange!" she exclaimed, drawing a long breath.
"Yes; but it's lots of fun, if it IS strange," remarked the small voice of the kitten, and Dorothy turned to find her pet walking in the air a foot or so away from the edge of the roof.
"Come back, Eureka!" she called, in distress, "you'll certainly be killed."
"I have nine lives," said the kitten, purring softly as it walked around in a circle and then came back to the roof; "but I can't lose even one of them by falling in this country, because I really couldn't manage to fall if I wanted to."
"Does the air bear up your weight?" asked the girl.
"Of course; can't you see?" and again the kitten wandered into the air and back to the edge of the roof.
"It's wonderful!" said Dorothy.
"Suppose we let Eureka go down to the street and get some one to help us," suggested Zeb, who had been even more amazed than Dorothy at these strange happenings.
"Perhaps we can walk on the air ourselves," replied the girl.
Zeb drew back with a shiver.
"I wouldn't dare try," he said.
"Maybe Jim will go," continued Dorothy, looking at the horse.
"And maybe he won't!" answered Jim. "I've tumbled through the air long enough to make me contented on this roof."
"But we didn't tumble to the roof," said the girl; "by the time we reached here we were floating very slowly, and I'm almost sure we could float down to the street without getting hurt. Eureka walks on the air all right."
"Eureka weights only about half a pound," replied the horse, in a scornful tone, "while I weigh about half a ton."
"You don't weigh as much as you ought to, Jim," remarked the girl, shaking her head as she looked at the animal. "You're dreadfully skinny."
"Oh, well; I'm old," said the horse, hanging his head despondently, "and I've had lots of trouble in my day, little one. For a good many years I drew a public cab in Chicago, and that's enough to make anyone skinny."
"He eats enough to get fat, I'm sure," said the boy, gravely.
"Do I? Can you remember any breakfast that I've had today?" growled Jim, as if he resented Zeb's speech.
"None of us has had breakfast," said the boy; "and in a time of danger like this it's foolish to talk about eating."
"Nothing is more dangerous than being without food," declared the horse, with a sniff at the rebuke of his young master; "and just at present no one can tell whether there are any oats in this queer country or not. If there are, they are liable to be glass oats!"
"Oh, no!" exclaimed Dorothy. "I can see plenty of nice gardens and fields down below us, at the edge of this city. But I wish we could find a way to get to the ground."
"Why don't you walk down?" asked Eureka. "I'm as hungry as the horse is, and I want my milk."
"Will you try it, Zeb" asked the girl, turning to her companion.
Zeb hesitated. He was still pale and frightened, for this dreadful adventure had upset him and made him nervous and worried. But he did not wish the little girl to think him a coward, so he advanced slowly to the edge of the roof.
Dorothy stretched out a hand to him and Zeb put one foot out and let it rest in the air a little over the edge of the roof. It seemed firm enough to walk upon, so he took courage and put out the other foot. Dorothy kept hold of his hand and followed him, and soon they were both walking through the air, with the kitten frisking beside them.
"Come on, Jim!" called the boy. "It's all right."
Jim had crept to the edge of the roof to look over, and being a sensible horse and quite experienced, he made up his mind that he could go where the others did. So, with a snort and a neigh and a whisk of his short tail he trotted off the roof into the air and at once began floating downward to the street. His great weight made him fall faster than the children walked, and he passed them on the way down; but when he came to the glass pavement he alighted upon it so softly that he was not even jarred.
"Well, well!" said Dorothy, drawing a long breath,