It was three minutes past three postmeridian in the operating room of the new Wireless Station recently installed at the United States Naval Observatory at Georgetown. Bill Hood, the afternoon operator, was sitting in his shirt sleeves with his receivers at his ears, smoking a corncob pipe and awaiting a call from the flagship Lincoln of the North Atlantic Patrol with which, somewhere just off Hatteras, he had been in commu-nication a few moments before. The air was quiet. Hood was a fat man, and so of course good-natured; but he was serious about his work and hated all interfering amateurs. Of late these wireless pests had become particularly obnoxious, as practically everything was sent out in code and they had nothing with which to occupy themselves. But it was a hot day and none of them seemed to be at work. On one side of his desk a tall thermometer indicated that the temperature of the room was 91 degrees Fahrenheit; on the other a big clock, connected with some extraneous mechanism by a complicated system of brass rods and wires, ticked off the minutes and seconds with a peculiar metallic self-consciousness, as if aware of its own importance in being the official timepiece, as far as there was an official timepiece, for the entire United States of America. Hood from time to time tested his converters and detector, and then resumed his non-official study of the adventures of a great detective who pursued the baffling criminal by the aid of all the latest scientific discoveries.