Off the mouth of the St. John's River, the tow was hove-to by a blank shot from a Government cruiser, and again was the Mermaid forced to seek safety at the bottom of the sea. This time she avenged herself by rising directly beneath the cruiser, and demonstrating to the Professor's entire satisfaction how easily he could if he chose place and fire a torpedo that would blow her from the water.
It had been decided to touch at Key West, the most southerly extremity of Florida, as well as of the United States, and only eighty-five miles across the Gulf Stream from Havana, and finally, after many narrow escapes from discovery, our adventurers reached the port of that quaint island-city in safety.
Here they found several American men-of-war, a small fleet of torpedo-boats, four revenue cutters, and a Spanish cruiser, to all of whom the strange tow, slowly making its way up the harbour, seemed an object of especial interest. Their fame had preceded them; every one knew that they were bound for Havana, and that they had been objects of suspicion all the way down the coast. So, before they came to anchor, they were boarded by United States officers, and a guard was placed on both tug and scow, with orders to allow no communication between them and the shore, except under strict surveillance.
In the meantime, the little Mermaid had sunk quietly out of sight, nor did she again rise to the surface until safely beneath a wharf covered with freight sheds, that extended out to deep water. Here, hidden in deepest shadow, she lay unobserved until nightfall, when our lads found no difficulty in gaining the streets of the town, leaving the Professor in charge of his beloved boat.
As Carlos Moranza had visited Key West before, he led the way without hesitation amid throngs of promenaders, among whom white was the rarest colour to be seen. Coal-black negroes from Jamaica, sallow-complexioned Spaniards, swarthy Cubans, mulattoes, quadroons, octoroons, and Creoles, with faces tinted in every shade of brown or yellow, jostled each other on the sidewalks, all talking, singing, or laughing, with eager gesticulations. Electric lights gleamed among the softly nestling leaves of tall cocoa-palms. Open carriages, bearing cigarette-smoking men in white linen, gaudily-clad negresses, or languid Cuban women, whose only sign of animation lay in their flashing eyes, rattled over the white pavements, while, above all, innumerable flags, displaying the blue and white stripes, the crimson field and single white star of Cuba Libre, fluttered in the faint night breeze.
The entire city, which is wholly Cuban in sympathy, as well as two-thirds so in population, was rejoicing over the news just received of an insurgent victory. The exulting throngs were most dense about the building occupied by an agent of the Cuban Junta, on a balcony of which the glad tidings were being read aloud from a paper just snatched off the press, while a guard stationed at the main entrance forbade admission, except to such persons as were of well-attested patriotism.
"Halt! You may not pass!" cried one of these, as our lads, having forced their way through the crowd, sought to enter.
For answer Carlos Moranza spoke a few words in so low a tone that only he might hear them.
Instantly the man stood aside, touched his cap respectfully, and motioned them to enter.
As they did so, a third person attempted to pass the guard in their company, but was seized on the threshold.
"Is this hombre of your party, señor?" asked the guard.
"Certainly not," replied Carlos. "I never saw him before."
So the intruder, who was evidently of Spanish blood, was ignominiously thrust back, and as he slunk away he muttered words that boded no good to Carlos Moranza, in case they should again meet.
In the meantime the young Cuban, accompanied by Carl Baldwin, made his way to the balcony where the agent of the Junta had just Finished reading of Garcia's victory. As Carlos touched him on the shoulder he turned quickly and frowned at sight of a stranger. Again the lad whispered his magic formula, and in another moment the agent was embracing him with the fervour of a life-long friendship. Then he led his guests to a private room, where for half-an-hour he engaged Carlos in earnest conversation, of which young Baldwin could only understand an occasional word.
When our lads finally left the building and regained the street, the latter asked curiously, "What was it all about, old man?"
"He said," replied Carlos, "that the Spanish cruiser now in port is here for the express purpose of escorting us to Havana, and that, as soon as we are outside Key West harbour, she will place a guard on both tug and scow."
"Hm!" remarked Carl Baldwin reflectively; "we can't allow that."
"I should say not," agreed Carlos Moranza; "only I'd like to know how we are to prevent it."
"Just you leave it to me, and I'll show you the trick," rejoined the young American.
CHAPTER III
So intent were the lads upon their conversation, that they mistook another freight shed for the one beneath which the Mermaid was hidden, and walked a few paces beside it before discovering their error. When they did so, they at once began to retrace their steps, and in turning a corner of the building came plump upon a cloaked figure evidently on their trail.
"Hello! what do you mean, sir, by following us?" cried Carl Baldwin, seizing the stranger's arm as he spoke.
With a muttered oath the man wrenched himself free and darted away, but not before the gleam of a street light had revealed his features to Carlos Moranza.
"The very fellow who tried to force his way into the quarters of the Junta!" he exclaimed, "and more than likely a Spanish spy. It is a narrow escape, my Carol, for if our blunder had not forced us to turn back, he must have discovered the Mermaid. In that case we should indeed have met with trouble."
"Let us hasten, then, before he returns."
"I don't believe he will dare do that. He is too badly scared."
But the spy did return, and, crouching in deepest shadow, became convinced that those whose business he was so anxious to discover had passed beneath the wharf. As he dared not attempt to follow them through the impenetrable gloom into which they had disappeared, he sought a hiding-place, and from it watched with infinite patience for them to again come forth.
They had, in the meantime, safely regained the snug living-room of the Mermaid, and reported all that had happened, to the Professor. Then Carl Baldwin unfolded his scheme for delaying the Spanish cruiser in port until after their departure.
As a result, the submarine boat was allowed to drift down the harbour with the ebbing tide, until she came abreast the great black hull of a man-of-war. Then she imperceptibly sank beneath the surface.
"She hovered like a gigantic fish."
The watch officer of the Spanish cruiser, leaning on her after-rail and gazing musingly down into the dark waters sweeping seaward, speculated idly concerning the stream of phosphorescent light tailing out from under her counter, but thought of it only as a natural phenomenon. Had he known that it was caused by the motion of the Mermaid's propeller necessary to hold her in position against the stream while she hovered like a gigantic fish directly above the screw of his ship, how easily could he have won the promotion for which he longed. But he suspected nothing; and as Carl Baldwin, working from the diving chamber of the submarine craft, had succeeded in fastening one end