The creature proved to be a full-grown herring-hog, weighing around four hundred pounds, and as this species destroys great numbers of foodfish, Mr. Choate made preparations to attack it.  Reaching the proper position, a hand harpoon was thrown by him.  It found its mark, and away went the great fish at so fast a clip that the line fairly smoked as it shot from the reel barrel.  In a few moments it was all out, and then the motor-boat gave a jump forward and rushed after the herring-hog.  He was towing it, as if it had been a chip!