"True," answered Oz. "But there is another way to make it float, which is to fill it with hot air. Hot air isn't as good as gas, for if the air should get cold the balloon would come down in the desert, and we should be lost."

"We!" exclaimed the girl. "Are you going with me?"

"Yes, of course," replied Oz. "I am tired of being such a humbug. If I should go out of this Palace my people would soon discover I am not a Wizard, and then they would be vexed with me for having deceived them. So I have to stay shut up in these rooms all day, and it gets tiresome. I'd much rather go back to Kansas with you and be in a circus again."

"I shall be glad to have your company," said Dorothy.

"Thank you," he answered. "Now, if you will help me sew the silk together, we will begin to work on our balloon."

So Dorothy took a needle and thread, and as fast as Oz cut the strips of silk into proper shape the girl sewed them neatly together. First there was a strip of light green silk, then a strip of dark green and then a strip of emerald green; for Oz had a fancy to make the balloon in different shades of the color about them. It took three days to sew all the strips together, but when it was finished they had a big bag of green silk more than twenty feet long.

Then Oz painted it on the inside with a coat of thin glue, to make it airtight, after which he announced that the balloon was ready.

"But we must have a basket to ride in," he said. So he sent the soldier with the green whiskers for a big clothes basket, which he fastened with many ropes to the bottom of the balloon.

When it was all ready, Oz sent word to his people that he was going to make a visit to a great brother Wizard who lived in the clouds. The news spread rapidly throughout the city and everyone came to see the wonderful sight.