as a theory by Mr. Parker, and no one cared to dispute him. The gold-seekers walked about, gazing on the ice caves with wonder showing on their faces.
It was almost like being in some fantastic scene from fairyland, the big ice bubbles representing the houses, the roofs being rounded like the igloos of the Eskimos. Some had no means of entrance, the outer surface showing no break. Others had small openings, like a little doorway, while of still others there remained but a small part of the original cave, some force of nature having crumbled and crushed it.
"Wonderful! Wonderful!" exclaimed Mr. Parker. "It bears out my theory exactly! Now to see how fast the ice is moving."
"How are you going to tell?" asked Tom
"By taking some mark on this field of ice, and observing a distant peak. Then I will set up a stake, and by noting their relative positions, I can tell just how fast the icefield is moving southward." The scientist hurried into the ship to get a sharpened stake he had prepared for this purpose.
"How fast do you think the ice is moving?" asked Ned.
"Oh, perhaps two or three feet a year."
"Two or three feet a year?" gasped Mr. Da-
