Thornton was the senior astronomer at the new Naval Observatory, and, with his junior associate, Evarts, had been the first scientist to observe the mysterious phenomena incident to the manifestations of Pax's power. But as Professor Hooker, at this point, remembered that he had left one of his other note-books at the Smithsonian, and as this note-book, when found, in turn suggested another unsolved problem, it was almost dark before he boarded the Georgetown car and quite naturally took his seat among the places reserved for smokers. The evening paper, however, offered very little of interest. In fact, Professor Hooker rarely found anything upon its front pages that he cared to read. The antics of political parties and their bosses, the matrimonial eccentricities of social leaders, "what the man will wear," even the vivid accounts of battle, murder, and sudden death with which its columns were replete meant nothing to him. Disgustedly he folded over the newspaper and ran his eye down the miscellaneous foreign-news items. An obscure paragraph caught his eye. THE NEW COMET Geneva, Switzerland--The officials of the observatory here have just published the corrected elements of the orbit of the new comet reported by Battelli last month. They predict that this new intruder into the solar system will be of unusual brilliancy, probably surpassing that of the Great Comet of 1811. Here was something worth while--something directly pertaining to Professor Hooker's bailiwick. Comets were his specialty. He had a familiar acquaintance with them and their families--knew them all by their first names, so to speak. Now, the Great Comet of 1811 had been the most sensational sidereal exhibition on record. It had caused a confident belief throughout the nations that the end of the world was surely at hand. If the new comet were going to be anything like that--holy smoke! The full moon was climbing over the ghostly white domes of the observatory as Professor Hooker, still pondering on the comet, trudged up the long hill to where his friend gave his life to the unselfish service of mankind. At the farther end of the building, a light glowed in a single window, and, having been admitted by a sleepy porter, he walked down the long corridor and knocked at Thornton's door. Receiving no response, he waited for a moment, knocked again, and then opened the door himself. Thornton was sitting at his desk, completely absorbed in his calculations.