“Stop it!” cried Mr. Filson for the second time; and just then the safety pin dropped out!

The first lookout had almost clutched the plunging cylinder as it passed him on its backward roll.

“Ware the bomb!” shouted his mate, and both of them leaped away from the vicinity of the peril.

Nor were they to be blamed.  With the pin out it was to be expected that the big bomb would immediately explode.  It banged against the rail, then charged across the deck again.  Every time it collided with an obstacle the spectators expected it to blow up and burst the after part of the ship asunder.

To the credit of Ensign Filson be it said that he did not fall back from his post on the quarter.  Nor did he directly order, now that he thought of it, any particular man to try to hold the plunging bomb.  It was work for a volunteer—­a man who was willing to take his life in his hands.

There is a quality of courage that is higher than that which takes men into battle along with their fellows.  The companionship of others in the charge breeds courage in many weak souls.

But to start alone on a dangerous mission, the lone man in an almost hopeless cause, calls for a steadiness of courage that few can rise to.

The four young fellows clinging together behind Mr. Filson were shot with fear, as they might very well be.  At any second the bomb was likely to explode, and they were so near that they could not possibly escape the full force of the blast.

Even if the chaser herself escaped complete destruction, they could not dodge the effect of the explosion; but like the ensign they would not retreat.

These bombs are timed to explode at about an eighty-foot depth.  A very few seconds would bring about the catastrophe.  Every man on the deck of the S. P. 888 felt that.

Suddenly, along the deck charged a sturdy figure—­a human battering ram.  The other men were knocked aside.  One of the lookouts was toppled over by the newcomer, falling flat upon his back and was shot by the next plunge of the craft into the scuppers amidships.

“Hi!  Hi!  Seven Knott!” yelled Al Torrance.

“Good old Colodia!  Go to it!” joined in the excited Frenchy.

Philip Morgan was already crouching for a leap.  Seven Knott passed him and threw himself upon the unleashed peril that rolled about the deck.

He grasped the cylinder as he fell, but it was snatched out of his arms by the next plunge of the vessel.  Seven Knott got to his knees and sought to seize the bomb again when it charged back across the deck.

The thing seemed actually to evade him; and swinging at an unexpected angle as Seven Knott threw himself desperately forward, the heavy cylinder banged the boatswain’s mate on the head.

The man was knocked down by the blow.  He suddenly straightened out and then relaxed, at full length, upon the sliding deck.  Like an inanimate lump his body followed the runaway bomb, but more slowly, to the lower rail.