A sharp blow with that knife would drive it to the handle through human flesh.

As he passed it slowly back and forth across his shoe, Harrigan watched the faces of the others with a side glance.
One or two looked up frankly and nodded approval when they saw his occupation.

The others, however, kept at their game, and of these the only one to pay no attention to his presence was Jerry Hovey.

It convinced Harrigan at once that the bos'n had given orders for his death.

It might have been the bos'n himself who had made the attempt just a moment before and had retreated to the forecastle.
On the other hand, the bos'n seemed to be breathing regularly, and the man with whom he had fought would not be able to keep his chest from heaving a little after that violent effort.