[Illustration: “Suddenly I heard the Professor’s voice just as if he were right out there on the desert.”] Author of _“The Radio Boys on the Mexican Border,” “The Radio Boys with the Revenue Guards,” “The Radio Boys on Secret Service Duty,” “The Radio Boys Search for the Inca’s Treasure,” “The Radio Boys Rescue the Lost Alaska Expedition,” “The Radio Boys in Darkest Africa.”_…
Or read it translated: 日本語 · 中文 · हिन्दी · Español · العربية · Français · বাংলা · Português · Русский · Bahasa Indonesia · اردو · Deutsch · Kiswahili · 한국어