The path soon led by the end of the great Upper Wetterhorn Glacier, and the Overall Boys begged their father to let them explore it.
"All right," said their father. "Just step into this small car and we will go on an exploring trip."
Before the boys knew what was happening, the tiny square car rose from the ground and began moving slowly upward, following the steep slope of the mountain.
"Oh, Jack, where are we going?" cried Joe. "This car is built bottom side up. The wheels are on the top of it, instead of on the bottom."
"That's so!" exclaimed Jack. "We are hanging in the air on a cable. It is lifting us right up the mountain side. And look away up there! Another car just like this one is coming down. My! Do you suppose we shall go as high as that?"
"We are hanging in the air on a cable," Jack exclaimed. "It is lifting us right up the mountain side"
"I hope so," said Joe. "But see what is below us. It is the glacier! Look at the great cracks in it. Do you hear that noise, Jack? It sounds like thunder."
"I guess it is only another crack bursting open," said Jack. "This hot sun makes the glacier move faster, and so it cracks open."
Up, up, climbed the car, right over the glacier, until it came to a wild goat's path on a narrow shelf of the mountain, more than twelve hundred feet above the starting point.