Again the Vulcan dashed at the diving terror as it disappeared and the cruiser swung clear around in a northerly tack. Her commander was trying to outguess the man under the sea.
A strange game of blind-man's-buff the three dissimilar crafts were playing. Caradoc assumed the submarine pilot would guess that the Panther had fled north, and he sent the tug spitting along a course that would lie between the cruiser and her enemy. The Panther was forced to repass the Vulcan in the new maneuver. The giant and pygmy were flying along at top speed, fairly abreast, scarcely five hundred yards apart.
Leonard took his eyes off the starboard sea a moment to look at the lion which this mouse was trying to nibble free, when suddenly, not thirty yards on the inside of the tug popped up the periscope.
The American rushed to the wheel, jerked it to the starboard. "Yonder! Yonder!" he bellowed in Caradoc's ear, pointing.
Again the guns shrilled forth; a steel sleet wailed about the Vulcan. Into the teeth of this blast, the tug circled and lunged.
With fascinated eyes, Madden watched the periscope cut a swirling circle on the midst of the beaten water and straighten on the Panther.
Now the metal eye was directly under their swaying starboard. A moment they sped side by side, toward the imperiled cruiser. Madden could almost have touched the wireless masts. A whine of bullets ripped one of their lifeboats like a saw and sputtered through the superstructure.
The periscope, which thrust six or seven feet out of water, disappeared under the swell of the Vulcan's hull. Suddenly the tug swung her blunt beak around with the sidelong blow of an angry swine. Madden went flying to the right rail of the bridge to stare down at the imminent tragedy.