“Books, and instruments from the laboratory,” was Bart’s contribution to the opinions. “But I, myself, don’t believe he is a burglar. Possibly he is some one whom Riggs hired to help out with the sweeping and dusting.”
“Let’s wait and see,” suggested Frank, and this was agreed to. Silently the chums, from their place of hiding, kept their eyes on the school. Presently there was a flicker of light in the windows of one of the upper rooms.
“There!” exclaimed Ned, “what did I tell you! He’s a new janitor, sweeping out,” for the light moved to and fro.
“What room is that?” asked Bart.
“Professor Long’s—the place where we’re bound for,” answered Frank.
“Hush! Not so loud,” pleaded Bart. “Some one may hear you, and get on to our trick. I guess you’re right. We’ll wait until he gets out of the way.”
“It may be a long time, and Fenn may come looking for us,” ventured Ned.
“Can’t help it,” decided Bart. “We can’t go in while the man is there.”
There seemed no way out of it, and the three chums crouched in the shadows, waiting. It was cold, and more than once they wished they had not started to play the joke on Fenn, but they were not going to give up now. They saw the light, moving to and fro, but it did not leave the room where they had first observed it—the classroom of Professor Long, the science teacher.
“He must be giving that a good cleaning,” remarked Bart. Hardly had he spoken than the light disappeared. A few minutes later it was visible on the floor below, and then it could be traced, as the person carrying it, descended.