Up above, in the tower, the midshipman bending over the compass, suddenly realized that daylight was filtering down through the water.  In another instant the midshipman glanced up to find the tower above the surface.

Yet Cadet Midshipman Osgoodby gasped as though he had intended to scream instead.  For, right ahead, her great bows looming up in the path of the little submarine, was a big liner, coming straight toward them!

CHAPTER XXI

“NO MORE MEN GO OVERBOARD!”

In a time like this a man’s coolness and nerve receive the utmost test.

Had Jack Benson been there at the wheel he would have swung both hands to the diving controls and shot below the surface.

But Cadet Osgoodby, now at the wheel, did not sufficiently understand the use of the diving controls.

Whatever was to be done had to be accomplished in the fewest seconds, or the little submarine craft was bound to be ground to scrap iron under the great bows of the steamship.

Both of the other midshipmen saw the danger in the same instant as did Midshipman Osgoodby.

Yet neither of these young men knew better what to do than did the third.  All they could do was to stiffen and to stand loyally beside their comrade in charge.

Perhaps for not half a second did Osgoodby hesitate.

Then he took the only chance that he saw; he threw the wheel over to port, jamming it there.

In strained, awful silence, the three waited.  Never had seconds seemed so long before—­not even under water.

On came the great liner, and now her bow was right atop of the bow at the forward end of the submarine’s platform deck.  There was just an instant to spare, but the “Farnum” shot past the oncoming, hostile-looking bows.  In another moment the little craft, now more than awash, was out of harm’s way.

None the less, the alarm had been passed on to those aboard the liner.  That great craft, bound up from South Africa, carried diamonds and gold coin, in the purser’s vaults in the hold, amounting in value to more than four million dollars.

All the way from Cape Town the passengers had been chaffing each other about the chance of meeting modern, up-to-date pirates.

“The only up-to-date pirate would be one that came in a submarine boat,” Captain Coster had laughingly told his passengers.  “A submarine boat could get away again, without leaving a trail.  In these days no other kind of pirate craft could long escape.”

So the passengers had joked each other about the submarine boat that would meet them, and rob the liner of its precious cargo.  Bets had laughingly been offered that the submarine pirate would be encountered off the coast of the United States.

Now, when the little craft shot up in the path of the big one, the bow watch of the “Greytown,” and a dozen passengers standing up in the bow, saw the little boat at the same time.