“Any sign of land yet, Nat?”

The professor put the question, as he stood beside the young leader of the Motor Rangers on the bridge of the Nomad.

“I’ve noticed a sort of purplish mass, like a low-lying reach of clouds, in the distance for some time,” was the rejoinder. “Do you think that it can be the coast of Chile?”

“I think it is highly probable; we should be picking up the land by this time. I think—heaven bless us!”

The professor clutched wildly at his head. But he was too late. His latest “top-piece,” a cap that had belonged to Ding-dong Bell, was whirled from his head into the sea.

“It’s an extraordinary thing,” he said with a kind of patient resignation. “But I don’t seem able to keep a hat on my head at all.”

“So I’ve noticed,” rejoined Nat, with a sort of dry humor, “and that’s the last spare one on board. You’ve had six since we left the volcanic islands, and there are no others left.”

“Well, I suppose I must go bareheaded, then, till we reach land. It is most annoying, though, really. I cannot account for it.”

Nat had a hard task to keep from laughing, but he managed to maintain a straight face by dint of heroic resolution. Moreover, as the bridge was protected by awnings of red and white striped material, he did not fear that the man of science would suffer greatly from the sun.

It speedily became evident that what Nat had seen was indeed the coast of Chile. By late afternoon they could make out the great mountain masses which hang above the rather low lying coast.

“Gives one a kind of a thrill to think that if all goes well we’ll be flying over those before long,” remarked Joe Hartley, as they all stood grouped on the bridge, watching the distant land with interest.

“It certainly does,” agreed Nat.

It was three weeks since they had parted company with the schooner, and the Nomad had been somewhat delayed by bad weather. But, all things considered, she had made a good run and all on board were in high good humor as they foresaw the end of the voyage.

By nightfall they were entering a landlocked bay that forms the harbor of Santa Rosa. It seemed to be a tiny place, as well as they could judge. Above the huddle of houses there rose the inevitable twin towers of the cathedral, however, and through the glasses they could make out, with a thrill, that Old Glory was flying over one of the buildings, no doubt the American consulate.

“I tell you, that old flag never looks so good as when you see it flying in a foreign port,” observed Mr. Tubbs, a sentiment which they all echoed.

As soon as they had anchored, their craft was surrounded by a fleet of boats from the shore. It was dark, and in the blackness the tiny lights carried by the swarming craft made them resemble a fleet of fire-flies, as Nat poetically remarked.

“I am going to take a boat ashore,” said Professor Grigg, as soon as everything had been made snug. “As we wish to start on the expedition as soon as possible it is important that I should see Mr. Stowe, the American consular agent, without delay. I am anxious, too, to know if the sections of the dirigible arrived in good shape.”

“By the way, professor,” asked Nat, “what is the airship’s name?”

“Why, bless my soul, I hadn’t thought of that,” remarked the man of science, “she ought to have one, too. What would you suggest?”

“I think Discoverer would be a good name,” said Joe.

“Dd-d-d-dish coverer?” inquired Ding-dong mildly.

In the scuffle that ensued, the lively young engineer of the Nomad was almost toppled overboard.

When quiet was restored, the professor said that he thought that Discoverer was a very good name. And so it was decided upon.

“You may come ashore with me, if you like,” said the professor to Nat.

“If I like,” echoed that lad; “of course I’d be delighted to,” he added.

Accordingly, a few minutes later they set out in one of the shore boats for the city, leaving behind them two youths with rather long faces. Ding-dong and Joe would have dearly loved to share in the expedition, but their presence on board was necessary, as the Nomad, after her long, rough cruise, was badly in need of a “general housecleaning.”

“I guess the consul will be astonished when he learns of the manner in which I have traveled here,” remarked the professor; “naturally he was expecting me on the schooner.”

“Speaking of the schooner,” said Nat as the native rowers propelled the long, narrow boat swiftly through the water, “you don’t anticipate any trouble from Lawless or Durkee?”

“No, I do not,” was the rejoinder; “in the first place, the schooner could not arrive here for many days, even if they had made up their minds to follow us. By that time we shall be, I hope, far advanced into the upper regions of Chile.”

As the professor spoke one of the boatmen gave a shout. Nat looked up and saw that a sailboat was bearing right down on them at tremendous speed. The outlines of two men could be seen, but it was too dark to distinguish their features.

“Good gracious, if that man doesn’t tack he’ll run us down!” cried the professor.

“He will indeed,” exclaimed Nat. “Hi there! Look out where you’re coming!” he yelled, adding his voice to the outcries of the boatmen.

But the occupants of the sailing craft paid no attention. At a terrific speed the larger craft bore straight down on the little boat.

The boatmen stood paralyzed with fear. They did nothing. Suddenly one of them dropped on his knees, and began imploring the protection of the saints.

Nat sprang toward him, almost upsetting the frail boat as he did so. With a quick movement he seized one of the paddle-like oars, and by exerting all his strength as he thrust it into the water, he managed to send the boat spinning out of harm’s way.

The next instant the sailing craft flashed by, almost grazing the bow of the small craft.

“You’re a nice pair of irresponsible idiots,” yelled the indignant Nat. “Do you know you almost ran us down?”

A yell of derision came from the other boat, and at the same instant something heavy whizzed past Nat’s head, almost striking him. It fell in to the water with a splash.

“They threw something at me, an iron weight, or a rock, or something,” exclaimed Nat as the sailboat, still going at the same rapid rate, vanished in the darkness. “What do you make of such conduct?”

“I don’t know what to think,” rejoined the professor. “I was inclined to believe at first that the sailors of that craft were merely careless. But the throwing of that weight puts a different complexion on the matter. It looks as if they deliberately tried to wreck us.”

“It does,” agreed Nat; “the whole thing is very mysterious. I’m sure I don’t know why any inhabitant of Santa Rosa should wish us harm.”

But further discussion of the matter was cut short by the necessity of arousing the boatmen, who were still stupid from fright. This was accomplished at last, and the boat was sent whizzing through the water again.

They were landed at a tumble-down wharf, and as the tide was out they got the full benefit of the odors inseparable from a South American town. Both, however, were too intent on the work in hand to waste much thought on this.

The professor, who spoke Spanish, as did Nat after a fashion, inquired the way to the consulate, and a ragged mestizo volunteered to escort him thither. But to their disappointment, when they reached the building, which served both as a dwelling and an office, the consul’s assistant informed them that he was not expected for an hour or more. They were invited to wait, however.

Professor Grigg, who was tired, gladly accepted the invitation, and sank into a comfortable chair. But sitting still didn’t much appeal to Nat.

“I guess I’ll stroll about the town a little and meet you here later,” he said to the professor after a few moments.

“Very well, my lad. But be careful,” was the reply.

“Oh, I’ll be very cautious,” laughed Nat; “at any rate, I can’t get run down by a boat ashore here.”

“But there may be dangers, nevertheless,” counseled the professor.

Nat again promised to be careful and hurried out. He wished to mail some letters home, as well as do a bit of sight seeing. He found the post office without difficulty and, having mailed his missives, was leaving it, when a native, in a long serape, or cloak, glided up to him.

“The seÑor is from the boat which anchored this evening?” he asked.

“Yes,” rejoined Nat. “Why?”

“Because if the seÑor wishes to see the town I am very good guide. I can show him where they sell veree fine ’Merican ice cream soda.”

“By ginger! You’re on,” cried Nat, who had a weakness for ice cream sodas; “lead on, Macduff. You don’t look very presentable, but I guess that isn’t your fault.”

“Thees way, seÑor,” said the man, and he walked off slightly in advance of Nat.

Suddenly he turned into a dark alley. Now, although Nat had nothing to dread, yet he began to be fearful that the fellow might mean to rob him. So he stopped short for an instant. But the next moment his suspicions were disarmed by a look at the ragged, pitiable fellow. Nat would have been a match for six of him.

“Where are you going?” he demanded, however, as they plunged into the narrow thoroughfare, which was ill-paved and black as a tunnel.

“A short cut, seÑor. A short cut to the Gran’ Plaza. We be there soon now.”

“Well, let’s hurry up and get out of this, quick,” said Nat; “I don’t much like——”

Smash!

Something struck the young Motor Ranger on the back of the head. He extended his arms helplessly, and plunged dizzily forward, collapsing in a heap on the pavement.

At the same instant two figures glided from a doorway and joined a third, the one who had struck Nat the blow that felled him.

“Good work, Manuello,” said the voice of Captain Lawless. “Pick him up and help us carry him in.”