"A signal, my friends! a signal!"
A pile was made of all the remaining combustibles—two or three planks and a beam. It was set fire to, and bright flames soon shot up ; but the strip of ice continued to melt and sink. Presently the little hill alone remained above water, and on it the despairing wretches, with the few animals left alive, huddled together, the bear growling fiercely.
The water was still rising, and there was no sign that any one on land had seen the signal. In less than a quarter of an hour they must all be swallowed up.
Could nothing be done to make the ice last longer? In three hours, three short hours, they might reach the land, which was now but three miles to windward.
"Oh!" cried Hobson, "if only I could stop the ice from melting! I would give my life to know how! Yes, I would give my life!"
"There is one way," suddenly replied a voice.
It was Thomas Black who spoke, the astronomer, who had not opened his lips for so long, and who had long since appeared dead to all that was going on.
"Yes," he continued, " there is one way of checking the dissolution of the ice — there is one way of saving us all."
All gathered eagerly round the speaker, and looked at him inquiringly. They thought they must have misheard what he said.
"Well?" asked Hobson, "what way do you mean?"
"To the pumps!" replied Black simply.
Was he mad? Did he take the ice for a sinking vessel, with ten feet of water in the hold?
The air pumps were at hand, together with the air vessel, which Hobson had been using as a reservoir for drinking water, but of what use could they be? Could they harden the ice, which was melting all over?
"He is mad!" exclaimed Long.
"To the pumps!" repeated the astronomer "fill the reservoir with air!"
"Do as he tells you!" cried Mrs Barnett.
The pumps were attached to the reservoir, the cover of which was closed and bolted. The pumps were then at once set to work, and the air was condensed under the pressure of several atmospheres. Then Black, taking one of the leather pipes connected with
