"it's all up with us now!" shouted andy. "i wish i had never come to the north pole!"

"how shall we escape?" yelled the professor.

not knowing what to do, the whole party stood still. behind them were the sea lions, roaring and snorting. in front of them, a hundred feet away were the bears, growling and howling.

"turn to the right!" cried jack. "there is a big hill of ice we can climb!"

the adventurers turned. as they did so mark glanced back at the sea lions, and uttered a cry of surprise.

"the lions are running away!" he shouted.

sure enough, the seals, though their progress could not be called "running" were retreating with their hitching, lumbering gait, away from the adventurers.

"but the bears are coming!" called andy.

"they aren't after us! it's the sea lions they want!" exclaimed jack. "i don't believe they will pay any attention to us!"

"the boy is right!" came from andy. "the bears want fresh meat and are going to tackle the lions. we're safe, but we'd better not stay around here long!"

jack's surmise was correct. the white bears did not follow the adventurers when the latter had run to the right. instead, increasing their pace, the polar bears sprang into the midst of the sea lions and soon there was a fierce battle between the two animal forces.

it was a fearful sight and the adventurers gazed at it in wonder, mingled with terror. the bears would seek to enfold the lions in their strong fore-paws, while the lions would try to sink their long tusks into the vitals of the enemy.

nearly a dozen had been killed on either side, but still the battle raged fiercely. the men and boys were so fascinated by the sight that they did not move, but stood staring from a small hummock of ice they had mounted.

"i think we had better go!" called professor henderson. "no telling when they will get tired of fighting each other and turn on us. besides i am anxious about the ship." and off they started.

the ship rested in the same position it had settled in when the gas contracted. no harm had come to it as the fall had been so gradual.

"i'll have the gas machine in operation in about an hour," professor henderson said. "meanwhile, bill, you and tom had better get some dinner for us. i'm hungry and i dare say the others are. have some hot coffee, for it is growing colder."

"i was thinking i didn't feel quite so warm," observed andy. "while there was a lot of excitement i didn't notice it, but now i am chilled through."

"no wonder," remarked the inventor. "it's forty degrees below zero!"

all were glad to go inside the ship which was warmed with gasolene stoves. bill and tom took off their heavy furs and began preparing a meal, which was soon smoking on the table. everyone had a good appetite, and, just as the boys, with andy and the two farmers were about to sit down, the professor came into the dining room.

"it's all right!" he exclaimed. "washington and i have the machine fixed. the gas is generating and we will be able to rise and continue our journey in about an hour."

this was good news, and, during the dinner the adventures of the morning were talked over in detail.

"we certainly had excitement enough for one day," observed jack.

rising from the table and donning their furs jack and mark went out on the deck. they glanced up at the gas bag, and found it was filling out from the pressure of the vapor being pumped into it from the machine.

"i wonder if we'd have time to walk out on the ice a little?" asked mark. "i haven't had a chance to look around, we've been so busy since we landed."

"we'll ask the captain," spoke jack. "i'd like a little stroll myself."

the inventor had no objections.

"don't go far away," he cautioned. "we'll start very soon now, and don't go near those animals."

the boys promised, and then, climbing over the rail, and down the ice hummocks they walked along a broad level expanse that stretched out for about a mile.

they had not gone far before jack, who was in the lead, came to a halt.

"look here!" he called to mark, who came hurrying up.

"what is it?"

"there's a pile of bones frozen into the ice! looks as if there had been a fight here between bears and sea lions, and this is all that was left. they ate each other up, all but the bones, which became covered with ice."

"those aren't animal bones, jack!"

"why not?"

"see, there is the skull of a man! and another! there are a dozen skulls!" and mark pointed to where they showed from underneath the crystal ice.

"you're right!" jack shouted. "and see! here is something that looks like a copper cylinder! maybe it has something inside! we must tell professor henderson!"

full of the importance of their discovery, the boys hastened back to the airship. the old inventor was much interested. directing washington to keep a careful eye on the gas machine, and taking an axe with him, the captain returned with the boys to where the bones were.

"they are certainly the remains of human beings," was the professor's opinion. "i don't know that it would be any service to dig them out, but that copper cylinder may be of value."

a few blows with the axe served to chop out the object. it was about two feet long and nearly three inches in diameter, and seemed to be securely sealed.

"we'll take it back to the ship and open it," said the inventor. "it is too cold to do it here."

back to the monarch they hurried. then, with a file, the professor removed one end of the copper case. from within he drew out a roll of paper, a watch, a knife and a few trinkets such as a man would carry about him.

"some white man did this!" exclaimed the old inventor, his hands trembling with eagerness as he unrolled the paper. "let us see if he has left any word behind to tell of his death."

all crowded around while amos henderson glanced at the mysterious message that had so curiously come to them. some of the writing was very faint, but by the aid of a magnifying glass it was deciphered. then, amid a deep silence the professor read the paper.

"whoever may find this, take warning and do not seek to find the north pole. danger lurks there. my name is andre christiansen, and i am a dane, educated in america, who set out to find the pole. i discovered it but was taken into captivity by the fierce people who dwell around it. they determined to get rid of me. with a party i was sent away. i was to be killed and buried in the ice. before they could kill me we were all attacked by polar bears. all the other men were killed and i was wounded. as i write this i am dying. i write it with my blood and a piece of bone. send word to denmark of my death, kind friend whoever you may be that finds this. if you reach this far in your search for the pole, be warned and go no farther. this is all i can write. i am nearly dead. i put the message in this copper cylinder which i brought along. i hope it will be found. good-bye."

for a few moments after the professor ceased reading the strange message no one spoke. they were all thinking of the terrible fate that had befallen andre christiansen; to die all alone in that icy land, yet who, in the agony of death had thought to warn some explorer who might come after him.

"poor fellow," murmured amos henderson. "he must have died soon after putting the message in the cylinder."

"and then the bears finished up their work by eating him and the men who wanted to kill him," said andy. "they left only the bones."

"how long ago do you suppose that was written?" asked jack.

"there is no telling," replied the professor. "but it must have been several years. i have read of all recent polar expeditions, and within the last twenty years there has been no one of this name to venture toward the pole. besides the copper cap on the cylinder has become rusted on, and that would indicate the passage of considerable time."

"i wonder if there are people at the pole?" came from mark.

"we'll go and see!" exclaimed the professor.

"you don't mean to say you are going further north after what that message says?" asked andy sudds.

"certainly; why not?"

"we may all be killed."

"we'll try not to have that happen," said the professor. "i am glad you boys found this. it is a valuable relic," and amos henderson put the message, the trinkets and the cylinder carefully away.

"i—i guess i won't go—" began andy.

at that instant the airship gave a sudden tremble. then the whole craft shivered. next it began to rise in the air.

"here we go!" cried the professor.