“WHAT is it?” asked Joe, as he hurriedly slipped on his clothing.

“Beyond me,” Bob answered. “Come on. Let’s go out on deck. We may be able to find out.”

The ship was rocking terribly, and the boys found it difficult to keep their footing. But they finally managed to catch hold of a rail, and from then on it was easier.

Several other passengers were up also, intent upon investigating the strange whistle.

“Maybe the boat’s sinking,” suggested Joe.

Bob shook his head.

“Probably isn’t that. At least let’s hope not.”

With beating hearts the youths came up to the glass and turned to look out at the angry sea. Then their expression changed.

A short distance from the Empire was a small fishing schooner, its prow out of sight in the water. On the stern stood a score or more men, waving their arms frantically. It was evident that they were panic-stricken, for several of them occasionally shouted for help. The little boat tossed about violently on the crest of the mountainous waves, her front deck gradually fading from view. Every minute it seemed that the end would come.

“It’s sinking fast!” cried Joe. “Why don’t some of our crew do something?”

“They are. Look.”

Farther up on the Empire’s deck fifteen or twenty men, under the direction of officers, were busy lowering lifeboats, although it looked out of reason to let them down on that sea.

Suddenly Bob turned and started toward his berth.

“Where you going?” Joe asked.

“To get the motion-picture camera. Here’ll be a good chance to take some pictures. There’s plenty of light around here.”

The next moment he was gone, and Joe turned to the deck.

The roar of the storm was deafening, and the wind howled ruefully through the funnels and masts. It was as though the end of the world were coming.

In less than five minutes two lifeboats were lowered, four or five men in each one. Then slowly they made their way toward the doomed schooner.

Bob now returned with the movie camera and cranked away, delighted to get an opportunity to film such an unusual happening.

The boys, however, were not the only ones to watch the daring attempt at rescue. In fact the glass was now crowded with people, and Mr. Holton, Mr. Lewis, and Professor Bigelow came up and wormed their way to their companions.

“Most thrilling thing I ever saw!” exclaimed Mr. Holton, as he breathlessly directed his gaze at the puny boats, which wallowed heavily and threatened to be swamped at every moment.

On and on went the rescue boats, their occupants bailing furiously. Now and then they threatened to capsize but always righted themselves.

In what seemed to be a long period of suspense to the spectators, the Empire’s crew reached the fishing schooner, which was now far under water.

One by one the fishermen climbed into the lifeboats, although it was necessary to give sharp commands to prevent disorder.

When the last of the men from the doomed boat stepped into the lifeboats, the officer in charge gave the word, and they started back to the Empire.

The return trip threatened to be more perilous, for the boats were very low in the water with the added load. Hurriedly the oarsmen set to work, so that they might be a good distance from the schooner when it sank, for a whirlpool would be created, meaning certain disaster to all around it.

Once a giant wave passed over the little boats and they disappeared from view, amid gasps from the spectators. But the danger was soon over, and the lifeboats emerged unharmed, the crewmen bailing rapidly.

They were barely at the Empire’s side when the schooner sank. With a last look at the scene of disaster, the fishermen boarded the ship. They were water-soaked and shivering with cold, but were too glad that they had been saved from the hungry depths of the sea to make any complaints.

“They’re Portuguese,” observed Professor Bigelow, as the fishermen came nearer.

The men muttered several words of thanks to the Empire’s crew, but it was clear that few understood them. Professor Bigelow, however, picked up the meaning at once and translated to his companions. Mr. Holton and Mr. Lewis had a slight knowledge of that language, but could not keep up with the excited men.

“The captain says it’s too bad they had to lose the schooner,” Professor Bigelow said. “He said they did their best to save it from going down, but had to give up. They did not intend to be this far at sea, but the storm gave them no chance of turning back.”

In a short time the excitement was over, and most of the passengers again retired, for the next morning they were to sight the West Indies.

Bob was overjoyed at the success he had had in taking the movies of the rescue and knew they would be a hit with the Neuman Film Corporation. They were the first of any importance that had been taken on the ship, and, as Joe said, a little action now and then does a lot to liven up a thing.

The next morning the storm had completely subsided, and true to schedule the Empire sighted Porto Rico. There was a scramble of passengers who had reached their destination.

“Probably think they’ll be carried on,” smiled Bob, as a rather nervous man fled down the stairs.

At first the shoreline was so dim as to be hardly distinguishable from the low clouds, but it gradually grew more plain. At last trees and houses could be made out, and then the skyline of San Juan loomed up in the distance.

“Looks like a city,” remarked Joe.

“It is,” his father replied. “Has over eighty-five thousand inhabitants.”

“Will we have time to go ashore?” asked Bob.

“Yes. The ship remains in port for about three hours,” Mr. Holton answered.

As the Empire approached the city, she backed her engines and moved slowly into port, where a small crowd of people were massed to give greeting.

Several other boats, large and small, were anchored at the busy docks, and the Empire steamed in between two freighters, one of which was being loaded with sugar.

“Sugar is one of the principal exports,” explained Professor Bigelow, as the exploration party prepared to leave the ship on a tour of the city.

As soon as they were in port, the gangplank was lowered. The adventurers made their way down, among a score of other passengers, many of whom were to leave the ship here.

Bob and Joe were at once impressed by the native residents, for there was a great variety of races. Spaniards were the most numerous, but there were also Negroes, mulattoes, French, Americans, and a small sprinkling of Indians.

“Quite a variety,” commented Joe. “Though it is possible to see this very thing in parts of New York.”

The explorers found that it would be comparatively easy to walk to various places of interest, and, after passing the former governor-general’s palace, they resolved to take in as much of the city as they could in two hours.

They found that the city was built on Morro Island, although the mainland could be easily reached by the numerous bridges. The streets were regularly laid out, and in the white quarters the residences were rather attractive.

“Doesn’t look much like America, though,” said Joe.

The exploration party reached the Empire with thirty minutes to spare, and they took chairs on deck to watch the busy dock below.

All too soon the whistle of leaving blew, and visitors scrambled down the gangplank. Then, with one long blast the ship slowly steamed out to sea, leaving Porto Rico behind.

At last they were on the final stretch. There would be no more stops till they reached South America. Then only short stays at Paramaribo and Cayenne, which were important seaport cities about two hundred miles apart.

“How long will it be until we again see land?” asked Bob, as he and the others sat on deck.

“Two days,” replied his father. “No doubt that they’ll seem like a long time, too.”

And they did. Bob and Joe were no more vexed than the others, however, for the men were also anxious to get started into the unknown. But when at last they did sight South America they forgot the past and looked into the future.

The boys, with their cameras in hand, were the first to reach the prow. They were closely followed by their fathers and the professor, who also crowded in for a first view.

At first, land was only a speck far out on the horizon. Then only gradually did it take on form and color.

“We’re nearing Paramaribo,” pronounced Mr. Holton, as he made out the outline of the city.

“What country is it in?” asked Joe.

“Dutch Guiana,” the professor answered. “One of the smallest nations in South America.”

The Empire steamed into a port nearly as busy as that of San Juan, although most of the boats were small.

For a second time the gangplank was lowered, and as the explorers had a half-hour to spare, they started on a short walking trip of the city.

“Quite a bit different from San Juan,” said Bob, as he noted that many of the people were native Indians.

The others nodded. None of them had been here before, and they naturally took a great interest in these unusual surroundings. In fact Professor Bigelow was the only one who had ever seen South America before, but this did not lessen his enthusiasm.

The streets were, for the most part, narrow and straight, cutting one another at right angles. The party was surprised to find the houses extremely low, hardly any of them exceeding two stories. Some were built of brick, but most were of cane plastered with mud.

Several minutes were spent in rambling over the various quarters of the city. Then they went back to the ship, which was now nearly ready to sail.

“South America is all right to visit,” remarked Joe, “but I don’t think I’d care to live here.”

The others agreed with him.

“And yet,” said Professor Bigelow, “there are a number of cities that are very well developed. Take Rio de Janeiro and Buenos Aires, for instance. They are large, clean, and well kept. A street in Buenos Aires looks very much like a street in the United States.”

Soon the Empire was off, having unloaded a large cargo of American goods. Several passengers also took their leave here.

From then on the scientific party was restless and eager to get started into the unknown. As one nears his goal, he nearly always finds it hard to wait through the last few stretches. Bob and Joe especially were excited, for it was their first adventure. Their hearts throbbed as they eagerly anticipated the coming days.

That evening they arrived in Cayenne, the capital of French Guiana, and, as before, took a short trip about the city. It was much the same as Paramaribo, however, and they were glad to board the Empire again for the last leg of the long journey.

It was about six hundred miles to MacapÁ, the Empire’s destination, and the party settled back in anticipation.

Neither of the boys did anything of importance. They were too enthusiastic over the coming great adventure.

“Let’s take it easy on deck,” suggested Bob, and they arranged chairs for all of the party that cared to rest.

“There’s nothing like enjoying the spell of the ocean,” remarked Mr. Holton.

A few days later Captain Crowell announced that they were sailing up the mighty Amazon, and the explorers were thrilled to the bone. The Amazon! At last one of their strongest ambitions had been fulfilled. Bob and Joe were overjoyous, for they had had a strong desire to see this great water system.

“Doesn’t look like a river to me,” said Joe as he tried in vain to see the shore.

“Over a hundred miles wide at the delta,” said Bob. “It’s the greatest river system in the world.”

For several hours they steamed on up the great river, past small settlements, plantations, and green islands. Occasionally they would get a glimpse of beautiful wild vegetation, and their hearts would beat fast. Then, almost without knowing it, they came to MacapÁ.

There was a fairly good port, and the vessel took her place between two small river steamers. The long ocean voyage had come to an end.