These were the conditions, then, when one bright Sunday the crew of an auxiliary cruiser were very busy cleaning ship—­a very thorough and absorbing business.  While the men were in the thick of the scrubbing, one of the crew stood up to straighten his back, and looked out through an open port in the vessel’s side.  As he looked he caught a glimpse of a low, black craft, hardly five hundred yards off, coming straight for the cruiser.  The water foamed at her bows and the black smoke poured out of her funnels, streaking behind her a long, sinister cloud.  It was one of those venomous little torpedo-boats, and she was apparently rushing in at top speed to get within easy range of the large warship.

“A torpedo-boat is headed straight for us,” cried the man at the port, and at the same moment came the call for general quarters.

As the men ran to their stations the word was passed from one to the other, “A Spanish torpedo-boat is headed for us.”

With haste born of desperation the crew worked to get ready for action, and when all was ready, each man in his place, guns loaded, firing lanyards in hand, gun-trainers at the wheels, all was still—­no command to fire was given.

From the signal-boys to the firemen in the stokehole—­for news travels fast aboard ship—­all were expecting the muffled report and the rending, tearing explosion of a torpedo under the ship’s bottom.  The terrible power of the torpedo was known to all, and the dread that filled the hearts of that waiting crew could not be put into words.

Of course it was a false alarm.  The torpedo-boat flew the Stars and Stripes, but the heavy smoke concealed it, and the officers, perceiving the opportunities for testing the men, let it be believed that a boat belonging to the enemy was bearing down on them.

The crews of vessels engaged in future wars will have, not only swifter, surer torpedo-boats to menace them, but even more dreadful foes.

The conning towers of the submarines show but a foot or two above the surface—­a sinister black spot on the water, like the dorsal fin of a shark, that suggests but does not reveal the cruel power below; for an instant the knob lingers above the surface while the steersman gets his bearings, and then it sinks in a swirling eddy, leaving no mark showing in what direction it has travelled.  Then the crew of the exposed warship wait and wonder with a sickening cold fear in their hearts how soon the crash will come, and pray that the deadly submarine torpedo will miss its mark.

Submarine torpedo-boats are actual, practical working vessels to-day, and already they have to be considered in the naval plans for attack and defense.

Though the importance of submarines in warfare, and especially as a weapon of defense, is beginning to be thoroughly recognised, it took a long time to arouse the interest of naval men and the public generally sufficient to give the inventors the support they needed.