At first he looked about him in a bewildered way, and then he seemed to recollect his whereabouts.  After an ineffectual attempt to speak, and move his limbs, he fixed his eyes with a meaning expression on the engines.

We had forgotten their stoppage.  Miss Carmichael sprang to investigate the cause.

“They are jammed,” she said after a short inspection.  “The essential part is jammed with the heat.  Whatever is to be done?”

We stared at each other blankly as the terrible import of her words came home to us.  Unless we could start the machines again, we must inevitably fall back on Mercury.  Perhaps we were falling now!

We endeavoured to think of a ready and practicable means of cooling the engines, but without success.  The water and oil on board was lukewarm; none of us knew how to make a freezing mixture even if we had the materials; our stock of liquid air had long been spent.

Miss Carmichael tried to make her father understand the difficulty in hopes that he would suggest a remedy, but all her efforts were in vain.  Carmichael lay with his eyes closed in a kind of lethargy or paralysis.

“Perhaps, when we are falling through the planet’s atmosphere,” said I, “if we open the scuttles and let the cold air blow through the room, it will cool the engines.”

“I’m afraid there will not be time,” replied Gazen, shaking his head; “we shall fall much faster than we rose.  The friction of the air against the car will generate heat.  We shall drop down like a meteoric stone and be smashed to atoms.”

“We have parachutes,” said Miss Carmichael, “do you think we shall be able to save our lives?”

“I doubt it,” answered Gazen sadly.  “They would be torn and whirled away.”

“So far as I can see there is only one hope for us,” said I.  “If we should happen to fall into a deep sea or lake, the car would rise to the surface again.”

“Yes, that is true,” responded Gazen; “the car is hollow and light.  It would float.  The water would also cool the machines and we might escape.”

The bare possibility cheered us with a ray of hope.

“If we only had time, my father might recover, and I believe he would save us yet,” said Miss Carmichael.

“I wonder how much time we have,” muttered Gazen.

“We can’t tell,” said I.  “It depends on the height we had reached and the speed we were going at when the engines stopped.  We shall rise like a ball thrown into the air and then fall back to the ground.”

“I wonder if we are still rising,” ejaculated Gazen.  “Let us take a look at the planet.”

“Don’t be long,” pleaded Miss Carmichael, as we turned to go.  “Meanwhile, I shall try and bring my father round.”

On getting to the observatory, we consulted the atmospheric pressure gauge and found it out of use, a sign that we had attained an altitude beyond the atmosphere of Mercury, and were now in empty space.