nine o'clock in the evening
Roy Mercer , like Charley and Lew , was a member of the Camp Brady Wireless Patrol . With his fellows he had taken part in the capture of the German spies who were trying to dynamite the Elk City reservoir and so wreck a great munitions centre during the war ; and with three other members of the Wireless Patrol , especially selected for their skill in wireless , he had later gone to New York with their leader , Captain Hardy , to assist the government Secret Service in its search for the secret wireless that was keeping the German Admiralty informed of the movements of American vessels . His fellows both envied and loved him . Roy warmly returned their affection , and his vessel never came into port that he did not , regularly at nine o'clock in the evening , flash out some message of greeting to his former comrades of the Wireless Patrol . It was always a one-sided conversation , however , because none of the boys in the Wireless Patrol owned a battery powerful enough to carry a message from Central City to New York . Just now each lad was engaged in trying to earn money so that the club could buy a battery or dynamo strong enough for this purpose . So each boy was working at any job he could pick up after school , and saving all he earned .