"We must get to them at once!" returned Captain Sumner.

The party were quickly on the snow, running toward the small boat, Bob and Jack leading.

When they came in sight of the craft a scene met their gaze which filled them with horror.

The madman had boarded the boat and was in the act of shoving off.

Terror-stricken, Mrs. Cromwell and Viola shrank back on the stern sheets.

"Stop! stop!" yelled Bob.

With a snarl the madman bent to his work. Soon the boat was in deep water.

In desperation Bob leaped into the water after it.

Ere he could reach the craft the madman picked up the long ice pole and aimed a vicious prod with it at our hero's breast.

Bob was struck squarely, and on the instant disappeared beneath the surface with the shrill laugh of the crazy sailor ringing in his ears.

Chapter VII.--A Fearful Fall.

"Where am I? Where are mother and Miss Viola?"

It was Bob who spoke. Jack Larmore stood over him in the snow.

"You're all right--I got you out of the water," Jack made answer.

"And the others?"

"Gone."

"Gone! In the power of that madman?"

"Yes."

Bob gave a groan and leaped up. His breast hurt him not a little.

"Where is Captain Sumner?"

"The yacht has given chase. Look!"

Jack pointed up the coast. The yacht was disappearing around a distant point.

But in a hour the vessel returned. The captain's sad face told his story. He had been unable to catch the crazy fugitive and rescue his daughter and Mrs. Cromwell.

What was to be done? Night came on rapidly, and they were compelled to wait until morning.

At early dawn Bob and Jack commenced to climb a near-by hill of ice to look for the small boat.

It was perilous work, but they did not falter.

At length they reached the level summit and glanced down.

The yacht looked beautiful as she lay to, with her topsails backed, and every movement of the figures on deck could be distinctly seen.

Crossing some rough, porous ice, they came to the pinnacle.

This was rougher than it had looked from below, and they found not much difficulty in mounting.

Soon they reached the summit, or, rather, within a few yards of it, where there was a tolerably safe and level spot.

With anxious speed, Bob extended the telescope, which he had carried slung over his shoulder.

For some time he swept the ocean in vain, but at length, far to the westward, just on the edge of the horizon, he caught sight of a white speck, which could be nothing but a sail.

"Look, Jack, and tell me what you think!" he exclaimed.

"I can see it!" cried the latter, after a lengthened search. "I agree with you--it must be a boat-sail; anyway, it's too distant to be a bird's wing. It must be many miles off."

"Let's make haste and descend!" cried our hero. "My chest, where the fellow struck me, is getting stiff up here in this rare air."

Most haste less speed.

They had reached within twenty feet of the level portion of the berg when our hero slipped.

His arm could not bear his weight, and he half fell, half slid rapidly to the bottom of the peak.

"Are you much hurt, old fellow?" exclaimed Jack, as soon as he could reach his friend's side.

"Only bruised, I think. Just help me up."

When a.s.sisted to his feet it was evident that Bob had twisted his ankle, or slightly strained it.

"Misfortunes never come alone," he said, with a laugh. "We must get on.

If I find the descent difficult, you must help me."

A stream of water from the melting of the ice on the peak ran along in a little channel it had worn, to where it came to the ravine.

Here it fell over in a cascade, and divided, one part, now joined by other trickling streams, descended the gorge into the sea, the other flowing into the mouth of an ice cavern.

The friends had crossed about half the summit of the berg when a sudden gust of wind, forming an eddy, blew up a cloud of ice dust.

These tiny particles stung like needle points when carried by the breeze against the faces of the two boys.