e most dangerous blocks lay beyond the
reach of his axe. However, he sent the smaller _debris_ in copious
showers down the precipice, and by cleverly rolling some comparatively
small boulders down upon those larger ones which lay out of reach, he
succeeded in dislodging many of them. This accomplished, he proceeded
to fix the stake on the upper surface of the glacier.

While he was thus occupied, the Professor assisted Lawrence in fixing
the theodolite, and then, leaving him, went to a neighbouring heap of
_debris_ followed by the Captain, whom he stationed there.

"I want you," he said, "to keep a good look-out and warn me as to which
way I must run to avoid falling rocks. Antoine has dislodged many of
them, but some he cannot reach. These enemies must be watched."

So saying, the Professor placed a stake and an auger against his breast,
buttoned his coat over them, and shouldered his axe.

"You don't mean to say that you're agoing to go under that cliff?"
exclaimed the Captain, in great surprise, laying his hand on the
Professor's arm and detaining him.

"My friend," returned the man of science, "do not detain me. Time is
precious just now. You have placed yourself under my orders for the
day, and, being a seaman, must understand the value of prompt obedience.
Do as I bid you."

He turned and went off at a swinging pace towards the foot of the
ice-cliff, while the Captain, in a state of anxiety, amounting almost to
consternation, sat down on a boulder, took off his hat, wiped his heated
brow, pronounced the Professor as mad as a March hare, and prepared to
discharge his duties as "the look-out."

Although cool as a cucumber in all circumstances at sea, where he knew
every danger and how to meet or avoid it, the worthy Captain now almost
lost self-control and became intensely agitated and anxious, insomuch
that he gave frequent and hurried false alarms, which he no less
hurriedly attempted to correct, sometimes in nautical terms, much to the
confusion of the Professor.

"Hallo! hi! look out--starboard--sta-a-arboard!" he shouted wildly, on
beholding a rock about the size of a chest of drawers spring from the
heights above and rush downward, with a smoke of ice-dust and _debris_
following, "quick! there! no! _port_! Port! I say it's--"

Before he could finish the sentence, the mass had fallen a long way to
the right of the Professor, and lay quiet on the ice not far from where
the Captain stood.

In