"I am pretty sure we can get away," was the opinion of the balloonist. "Even if our gas container is so damaged that it will not sustain us, we are still an aeroplane, and this roof being flat will make a good place to start from. No, we can leave as soon as this storm lets up a little."
"Then I'm going to have a look and find out what sort of a building this is," declared Tom, and, while Mr. Sharp began a survey, as well as he could in the dark, of the airship, the young inventor proceeded cautiously to ascertain the extent of the roof.
The rain was not coming down quite so hard now, and Tom found it easier to see. Mr. Damon, finding he could do nothing to help, went back into the cabin, blessing himself and his various possessions at the queer predicament in which they found themselves.
Flashing his light every few seconds, Tom walked on until he came to one edge of the roof. It was very large, as he could judge by the time it took him to traverse it. There was a low parapet at the edge. He peered over, and an expanse of dark wall met his eyes.
"Must have come to one side," he reasoned. "I want to get to the front. Then, maybe, I can see a sign that will tell me what I want to know."
The lad turned to the left, and, presently came to another parapet. It was higher, and ornamented with terra-cotta bricks. This, evidently, was the front. As Tom peered over the edge of the little raised ledge, there flashed out below him hundreds of electric lights. The city illuminating plant was being repaired. Then Tom saw flashing below him one of those large signs made of incandescent lights. It was in front of the building, and as soon as our hero saw the words he knew where the airship had landed. For what he read, as he leaned over, was this:
MIDDLEVILLE ARCADE
Tom gave a cry.
"What's the matter?" called Mr. Sharp.
"I've discovered something," answered Tom, hurrying up to his friend. "We're on top of the Middleville Arcade building."