"Listen! I will take the exact bearings of this spot, and give them to you, so that, upon your return to England, you can tell our countrymen about it, and let them have a share, if you think that so much gold would make them happy."

"Ah! master, I give up; I see that you are right, and that there is nothing else to be done. Let us fill our car with the precious mineral, and what remains at the end of the trip will be so much made."

And Joe went to work. He did so, too, with all his might, and soon had collected more than a thousand pieces of quartz, which contained gold enclosed as though in an extremely hard crystal casket.

The doctor watched him with a smile; and, while Joe went on, he took the bearings, and found that the missionary's grave lay in twenty-two degrees twenty-three minutes east longitude, and four degrees fifty-five minutes north latitude.

Then, casting one glance at the swelling of the soil, beneath which the body of the poor Frenchman reposed, he went back to his car.

He would have erected a plain, rude cross over the tomb, left solitary thus in the midst of the African deserts, but not a tree was to be seen in the environs.

"God will recognize it!" said Kennedy.

An anxiety of another sort now began to steal over the doctor's mind. He would have given much of the gold before him for a little water--for he had to replace what had been thrown overboard when the negro was carried up into the air. But it was impossible to find it in these arid regions; and this reflection gave him great uneasiness. He had to feed his cylinder continually; and he even began to find that he had not enough to quench the thirst of his party. Therefore he determined to lose no opportunity of replenishing his supply.

Upon getting back to the car, he found it burdened with the quartz-blocks that Joe's greed had heaped in it. He got in, however, without saying any thing. Kennedy took his customary place, and Joe followed, but not without casting a covetous glance at the treasures in the ravine.

The doctor rekindled the light in the cylinder; the spiral became heated; the current of hydrogen came in a few minutes, and the gas dilated; but the balloon did not stir an inch.

Joe looked on uneasily, but kept silent.

"Joe!" said the doctor.

Joe made no reply.

"Joe! Don't you hear me?"

Joe made a sign that he heard; but he would not understand.

"Do me the kindness to throw out some of that quartz!"

"But, doctor, you gave me leave--"

"I gave you leave to replace the ballast; that was all!"

"But--"

"Do you want to stay forever in this desert?"

Joe cast a despairing look at Kennedy; but the hunter put on the air of a man who could do nothing in the matter.

"Well, Joe?"

"Then your cylinder don't work," said the obstinate fellow.

"My cylinder? It is lit, as you perceive. But the balloon will not rise until you have thrown off a little ballast."

Joe scratched his ear, picked up a piece of quartz, the smallest in the lot, weighed and reweighed it, and tossed it up and down in his hand. It was a fragment of about three or four pounds. At last he threw it out.

But the balloon did not budge.

"Humph!" said he; "we're not going up yet."

"Not yet," said the doctor. "Keep on throwing."

Kennedy laughed. Joe now threw out some ten pounds, but the balloon stood still.

Joe got very pale.

"Poor fellow!" said the doctor. "Mr. Kennedy, you and I weigh, unless I am mistaken, about four hundred pounds--so that you'll have to get rid of at least that weight, since it was put in here to make up for us."

"Throw away four hundred pounds!" said Joe, piteously.

"And some more with it, or we can't rise. Come, courage, Joe!"

The brave fellow, heaving deep sighs, began at last to lighten the balloon; but, from time to time, he would stop, and ask:

"Are you going up?"

"No, not yet," was the invariable response.

"It moves!" said he, at last.

"Keep on!" replied the doctor.

"It's going up; I'm sure."

"Keep on yet," said Kennedy.