What did it mean?
Of course, they must have fallen into something of the sort. Their disappearance could be explained in no other way.
Frank placed his penstock under a corner of the huge block of ice. He was not able to lift it, but the penstock slipped down into a certain cavity beneath.
“Give me a hand, Randall,” he said.
Together they tried to lift the block of ice, but it would not budge. Their strength was not adequate.
Frank was in a quandary.
He knew that his two colleagues were somewhere beneath that immovable block of ice which had fallen into just the position to close the cavity into which they had fallen.
How deep the pitfall was he had no means of guessing. He placed his ear to the crack and listened. No sound came up.
Various horrible possibilities occurred to Frank.
Suppose the cavity was so deep that it extended all the way down to the water, or was really in itself an air-hole? They would certainly go to the bottom of the sea.