"Quite," replied the professor, solemnly. "Professor Tapper is one of our greatest savants."

"But so was your friend who told you the Patagonians were a friendly tribe," argued Frank.

"I am quite sure that Professor Tapper could not have been mistaken, however."

"Has Professor Tapper ever been in the South Polar regions?" asked Billy, seriously.

"Why, no," admitted the professor; "but he has proved that there must be a fur-bearing pollywog down here."

"In what manner has he been able to prove it?" asked Harry.

"He has written three volumes about it. They are in the Congressional library. Then he contributed a prize-essay on it to the Smithsonian Inst.i.tute, which has bound it up with my report on the Canadian Bull Frog. He is a very learned man."

"But the South Polar pollywog is then only a theory?"

"Well, yes--so far," admitted the professor; "but it is reserved for me to gain the honor of positively proving the strange creature's existence."

"And if there should be no such thing in existence?" asked Frank.

"Then I shall write a book denouncing Professor Tapper," said the professor, with an air of finality, and turning away to examine the water through a pair of binoculars.

On moved the ships and at last, early one day, Captain Barrington called the boys on deck and, with a wave of the hand, indicated a huge white cliff, or palisade, which rose abruptly from the green water and seemed to stretch to infinity in either direction.

"The Great Barrier," he said, simply.

"Which will be our home for almost a year," added Captain Hazzard.

The boys gazed in wonder at the mighty wall of snow and ice as it glittered in the sunlight. It was, indeed, a Great Barrier. At the point where they lay it rose to a height of 130 feet or more from the water, which was filled with great detached ma.s.ses of ice. Further on it seemed to sweep to even greater heights.

This was the barrier at which Lieutenant Wilkes, on his unlucky expedition, had gazed. The mighty wall that Shackleton and Scott, the Englishmen, had scaled and then fought their way to "furthest South"

beyond. The names of many other explorers, French, English, Danish, and German, rushed into the boys' minds as they gazed.

Were they destined to penetrate the great mysteries that lay beyond it? Would their airship be successful in wresting forth the secret of the great white silence?

"Well?" said Captain Barrington, breaking the silence at length, with a smile; "pretty big proposition, eh?"

The boys gazed up at him awe-struck.

"We never dreamed it was anything like this," said Frank. "I always pictured the Great Barrier as something more or less imaginary."

"Pretty solid bit of imagination, that ice-wall yonder," laughed Captain Hazzard.

"How are we ever going to get on the top of it?" asked Billy.

"We must steam along to the westward till we find a spot where it shelves," was the reply.

"Then it is not as high as this all the way round the polar regions?"

"No, in places it shelves down till to make a landing in boats is simple. We must look for one of those spots."

"What is the nature of the country beyond?" asked Frank, deeply interested.

"Ice and snow in great plateaus, with here and there monster glaciers," was the reply of Captain Hazzard. "In places, too, immense rocky cliffs tower up, seeming to bar all further progress into the mystery of the South Pole."

"Mountains?" gasped Billy.

"Yes, and even volcanoes. This has given rise to a supposition that at the pole itself there may be flaming mountains, the warmth of which would have caused an open polar sea to form."

"n.o.body knows for certain, then?" asked Frank.

"No, n.o.body knows for certain," repeated Captain Hazzard, his eyes fixed on the great white wall. "Perhaps we shall find out."

"Perhaps," echoed Frank, quite carried away by the idea.

"What is known about the location of the pole?" asked Billy.

"It is supposed to lie on an immensely high plateau, possibly 20,000 feet above sea level. Shackleton got within a hundred miles of it he believes."

"And then he had to turn back," added Captain Barrington.

"Yes; lack of provisions and the impossibility of traveling quickly after his Manchurian ponies had died compelled him to leave the mystery unsolved. Let us hope it remains for the American flag to be planted at the pole."

"Are there any animals or sea-creatures there, do you know?" inquired the professor, who had been an interested listener.

"If there is an open polar sea there is no doubt that there is life in it," was the answer, with a smile; "but what form such creatures would a.s.sume we cannot tell."

"Perhaps hideous monsters?" suggested the imaginative Billy.

"More likely creatures like whales or seals," returned Captain Hazzard.

"If there is such a thing as a creature with a South Polar flea in its fur I would like to catch it," hopefully announced the scientist.

"Seals are covered with them," rejoined the officer.

"Pooh, those are just common seal-fleas," returned the professor. "I would like to find an insect that makes its home at the pole itself."

"Well, perhaps you will," was the rejoinder.

"I hope so," said the professor. "It would be very interesting."

All this time the two vessels were steaming slowly westward along the inhospitable barrier that seemed, as Frank said, to have been erected by nature to keep intruders away from the South Polar regions. As the professor concluded his last remark the lookout gave a sudden hail.

"Shipwrecked sailors!"

"Where away?" shouted Captain Barrington.

"Off to the starboard bow, sir," came back the hail.