Koku glared at everybody who came anywhere near his master. He marched up and down within a stride or two of Tom, and flexed his big muscles and muttered threats in his own tongue. The half civilized creature, who was usually the mildest person imaginable, had now become a figure to strike terror to the bravest. Before anything further was done to the keel of the flying boat Tom made an exhaustive examination of the traveling crane, the cables attached to it, and the steel rail from which its truck hung. He trusted the engineman, who was an old employee. And he could not think of any man or boy about the erecting shop that wished the company—or himself—ill. “It’s a jinx, boss,” declared one of the older men. “Bad luck! And I have a feeling in my bones that it’s only the beginning.” “Come, Carney!” commanded Tom Swift. “You take something to get rid of any such feeling. Don’t talk that way and let the other men hear you. Of course there is a perfectly reasonable explanation of the accident.” “That doesn’t stop it from being bad luck just the same,” muttered the man. A thorough scrutiny of the line of the crane’s travel finally resulted in a single explanation of the accident. Tom picked up a loop of steel cable—a piece perhaps two feet long when straightened—which showed marks of the wheels of the traveler. “This loop must have been left hanging to the rail by some careless repair man and, after that last trip of the crane, it shifted and slid along the rail to that spot where the machinery fouled,” Tom declared. “Now, somebody is at fault in this. It has cost the Swift Construction a great deal of money for employees’ compensation, as well as the wage loss for this breakdown. If I ever find out who the careless man is, I’ll fire him. Carelessness is the most dangerous thing in the world. Our lives are not safe when such a man is around. Now let’s see what more we can do about laying this keel.” It did seem, however, as though the old machinist had somehow hit it right about the “jinx.” Bad luck seemed to accompany the assembling of the body of the flying boat. Little accidents happened daily. Men were hurt, tools were broken, delays occurred. Tom got into a touchy state that even Ned Newton recognized. “You’d better knock off on this flying boat and get a change of action,” Ned advised. “Go somewhere with Mary and her mother. Take a rest.” “You’d better take a rest yourself,” returned Tom sharply, but grinning. “I would fly all to pieces just now if I had to be idle. You know how it is with me, Ned. I have to work it off. And I can think or talk about nothing now but the _Winged Arrow_.” “It looks to me,” said the pessimistic Ned, “that that is one arrow that will never be shot. I have been looking it over, and all it seems to be is a great pontoon—as clumsy as can be.” “You are a cheerful beggar!” snapped Tom Swift. “What do you expect to see at this stage of the work, I’d like to know?”