He inspected the chart and measured the distance in an airline from Boston to the point where the red lines converged. It was a trifle less than the distance between Boston and Chicago. Burke had done that in nine hours on the trial trip of his trans-Atlantic monoplane. If the machine was in order and Burke started in the morning he would be with them by sunset, if he didn't get lost. But Bennie knew that Burke could drive his machine by dead reckoning and strike within a few leagues of a target a thousand miles away. A muffled roar outside interrupted his musings, and running out on the platform again he found Atterbury attaching the cord of the aluminum ribbon, which the rocket had carried up and over the antennae, to one of the brush bars of the alternator. "Nearly ready, sir," he said. "We'd best--lock the storm bolts--to hold her down--in case we have--to crowd on the power. We've got to use--pretty near the full lift--to get the alternator up--to the proper speed." A chill ran down Bennie's spine. They were going to start the engine! In a moment he would be within twenty feet of a blast of disintegration products capable of lifting the whole machine into the air, and it was to be started at his command, after he had worked and pottered for two years with a thermic inductor the size of a thimble! He felt as he used to feel before taking a high dive, or as he imagined a soldier feels when about to go under fire for the first time. How would it turn out? Was he taking too much responsibility, and was Atterbury counting on him for the management of details? He felt singularly helpless as he reentered the chart room to compose his message. He turned on the electric lamp which hung over the desk, for in the fast-gathering dusk the interior of the Ring was in almost total darkness. How should his message read? It must be brief: it must tell the story, and, above all, it must be compelling. He was joined by the electrician. "I think--we are all--ready now," stammered the latter. "What will you send, sir?" Bennie handed him a scrap of yellow paper, and Atterbury put on a pair of dark amber glasses, to protect his eyes from the light of the spark. "_Thornton, Naval Observatory, Washington:_ "Stranded fifty-four thirty-eight north, seventy-four eighteen west. Have the Ring machine. Ask Burke come immediately. Life and death matter. "B. HOOKER." Atterbury read the message and then gazed blankly at Hooker. "I--don't--understand," he said. "Never mind, send it. I'll explain later." Together they went into the condenser room.