“We can remain here as long as we like, suspended between the Sun and Mercury,” replied Gazen.

“Is it better to linger and die in a living tomb than be dashed to pieces and have done with it?”

“But we shall gain time for your father to recover.”

“I am afraid my father will never recover in this place.  The heat is killing him.  Unless we can get further away from the sun he will die, I’m sure he will.”

Her eyes filled with tears.

“Don’t distress yourself, dear Miss Carmichael, please don’t,” said Gazen tenderly.  “Now that we have time to think, perhaps we shall hit upon some plan.”

An idea flashed into my head.

“Look here,” said I to Gazen, “you remember our conversation in your observatory one day on the propelling power of rockets—­how a rocket might be used to drive a car through space?”

“Yes; but we have no rockets.”

“No, but we have rifles, and rifle bullets fired from the car, though not so powerful, will have a similar effect.”

“Well?”

“The car is now at rest in space.  A slight impulse will direct it one way or another.  Why should we not send it off in such a way that in falling towards Mercury it will not strike the planet, but circle round it; or if it should fall towards the surface, will do so at a great slant, and allow the atmosphere to cool the engines.”

“Let me see,” said Gazen, drawing a diagram in his note-book, and studying it attentively.  “Yes, there is something in that.  It’s a forlorn hope at best, but perhaps it’s our only hope.  If we could only get into the shadow of the planet we might be saved.”

As delay might prove fatal to Carmichael, and since it was uncertain whether he could right the engines in their present situation, we decided to act on the suggestion without loss of time.  Gazen and I calculated the positions of the rifles and the number of shots to be fired in order to give the required impetus to the car.  The engine-room, being well provided with scuttles, was chosen as the scene of our operations.  A brace of magazine rifles were fixed through two of the scuttles in such a way that the recoil of the shots would urge the car in an oblique direction backwards, so as to clear or almost clear the planet, allowance being made for the forward motion of the latter in its orbit.  Needless to say, the barrel of each rifle was packed round so as to keep the air in the car from escaping into space.

At a given signal the rifles were discharged simultaneously by Gazen and myself.  There was little noise, but the car trembled with the shock, and the prostrate man opened his eyes.

Had it produced the desired effect?  We could not tell without an appeal to the telescope.

“I’ll be back in a moment,” cried Gazen, springing upstairs to the observatory.

“Do you feel any better, father?” enquired Miss Carmichael, laying her cool hand on the invalid’s fevered brow.