“That’s funny,” said Mark to himself. “I could almost swear I saw some one go into that room. Yet I know the professor did not enter, for I just left him. And none of the others would dare to. I wonder if I will ever solve the mystery.”
But he had too much to do to allow him to dwell on that matter. Several of the dynamos needed adjusting and for two hours he and Jack had all they could do.
In the meanwhile the professor had gone over the other parts of the ship, and gotten everything in readiness for the descent. The Mermaid was lowered to within a few hundred feet of the sea, and, through a hose that was let down, the compartments, provided for this emergency were filled with water. These compartments were between the outer and inner hulls of the lower part of the craft, and were designed to prevent the interior becoming heated in case the travelers found they had to pass close to fire. There were also vacuum chambers, and from these the air was exhausted, as of course every schoolboy knows a vacuum is a non-conductor of either heat or cold.
“Now I think we are ready,” the professor announced at length.
“Everything’s all right in the engine room,” announced Jack.
“Yes, an’ everything’s all right in th’ kitchen,” put in Washington. “I’ve got a good meal ready as soon as any one wants to eat.”
“It will have to wait a while,” Mr. Henderson remarked. “We are going to start to make the descent before we dine.”
The hose was reeled up, and the ship was sent a few hundred feet higher into the air, as Mr. Henderson wanted to take a last good observation before he went down into the hole.
But having risen some distance above the masses of rolling vapors he found he was at no advantage, since the strongest telescope he could bring to bear could not pierce the cloud masses.
“We’ll just have to trust to luck,” the scientist said. “I judge we’re about over the centre of the opening. Lower away Mark!”