The Pony Rider Boys in the Ozarks; Or, The Secret of Ruby Mountain - Frank Gee Patchin - Bog

"Boys! B-o-y-s!" There was no response to the imperative summons. Professor Zepplin sat up in his cot, listening intently. Something had awakened him suddenly, but just what he was unable to decide. "Be quiet over there, young men," he admonished, adding in a lower tone, "I'm sure I heard some one moving about."