Suddenly Jack, who happened to glance up, gave a loud cry.  All the others stopped their digging.

“Here come the Esquimaux!” yelled the boy.  “I just saw them around that big iceberg!”

This was alarming news.  Old Andy dropped his shovel and scrambled over the side of the ship.

“What’s de matter?  Am yo’ skeered?” asked Washington.

“Not a bit of it!” cried Andy.  “I want to get a gun and give those fellows something to remember me by!”

“Never mind them!” shouted the professor.  “Get the ship free and we need not stay to fight them.  We are almost ready to start!”

But Andy was bound to have a shot at the savages, and he grabbed up his rifle, which was fully loaded, and came out on the deck.

The natives came on with a rush.  There were about two hundred of them, and they had arrived on several big sleds.  The Esquimaux who had piloted the adventurers back to their ship had disappeared, for he knew he would be killed as a traitor if his tribesmen caught him.

“Come on!” cried Bill to Tom and the boys.  “Let’s get aboard.  We’ll be killed!”

“You can go!” shouted Jack.  “I’m going to stay down here and free the ship from ice.  That’s the only thing to do.”

“I’ll stay with you!” exclaimed Mark.

Tom and Bill scrambled up the sides of the ship and disappeared into the cabin.  The boys remained on the ice, partly under the airship, chipping and picking to free the bottom.

With loud shouts and yells the Esquimaux surrounded the Monarch.  The savages were armed with bows and arrows, and soon a shower of these missiles were shot toward the craft.

Professor Henderson was in mortal terror lest one of the sharp weapons would pierce the gas bag, but, for some reason, the natives fired at the lower part of the ship.  Andy and the two helpers were now ready to return the fire.  Their guns rattled out and the reports caused the natives great astonishment.

The first shots the defenders had fired over the heads of the Esquimaux, not wishing to kill them if they could help it.  But though the reports caused a momentary falling back, the attackers soon rallied again, and shot a thicker cloud of arrows, some of which fell uncomfortably near.

“Let ’em have it right in the faces this time!” shouted Andy.

He took careful aim at the mass of natives who were advancing, and one fell.  Bill and Tom followed his example, and the onslaught was checked for a time.

But now reinforcements to the Esquimaux arrived until there were fully five hundred of the fur-clad savages out on the ice surrounding the airship.  To cope with such a force seemed madness.  Bill received a slight wound in the arm, and Tom had a narrow escape from being killed, a big spear just missing his head.

“Drop down below the rail!” yelled Andy.  “They can’t hit us so easy then, and we can fire just as good!”