"Only eleven left," said he.

Thereupon the birds changed their tactics, and by common consent soared above the balloon. Kennedy glanced at Ferguson. The latter, in spite of his imperturbability, grew pale. Then ensued a moment of terrifying silence. In the next they heard a harsh tearing noise, as of something rending the silk, and the car seemed to sink from beneath the feet of our three aeronauts.

"We are lost!" exclaimed Ferguson, glancing at the barometer, which was now swiftly rising.

"Over with the ballast!" he shouted, "over with it!"

And in a few seconds the last lumps of quartz had disappeared.

"We are still falling! Empty the water-tanks! Do you hear me, Joe? We are pitching into the lake!"

Joe obeyed. The doctor leaned over and looked out. The lake seemed to come up toward him like a rising tide. Every object around grew rapidly in size while they were looking at it. The car was not two hundred feet from the surface of Lake Tchad.

"The provisions! the provisions!" cried the doctor.

And the box containing them was launched into space.

Their descent became less rapid, but the luckless aeronauts were still falling, and into the lake.

"Throw out something--something more!" cried the doctor.

"There is nothing more to throw!" was Kennedy's despairing response.

"Yes, there is!" called Joe, and with a wave of the hand he disappeared like a flash, over the edge of the car.

"Joe! Joe!" exclaimed the doctor, horror-stricken.

The Victoria thus relieved resumed her ascending motion, mounted a thousand feet into the air, and the wind, burying itself in the disinflated covering, bore them away toward the northern part of the lake.

"Lost!" exclaimed the sportsman, with a gesture of despair.

"Lost to save us!" responded Ferguson.

And these men, intrepid as they were, felt the large tears streaming down their cheeks. They leaned over with the vain hope of seeing some trace of their heroic companion, but they were already far away from him.

"What course shall we pursue?" asked Kennedy.

"Alight as soon as possible, Dick, and then wait."

After a sweep of some sixty miles the Victoria halted on a desert shore, on the north of the lake. The anchors caught in a low tree and the sportsman fastened it securely. Night came, but neither Ferguson nor Kennedy could find one moment's sleep.

CHAPTER THIRTY-THIRD.

Conjectures.--Reestablishment of the Victoria's Equilibrium.--Dr. Ferguson's New Calculations.--Kennedy's Hunt.--A Complete Exploration of Lake Tchad.--Tangalia.--The Return.--Lari.

On the morrow, the 13th of May, our travellers, for the first time, reconnoitred the part of the coast on which they had landed. It was a sort of island of solid ground in the midst of an immense marsh. Around this fragment of terra firma grew reeds as lofty as trees are in Europe, and stretching away out of sight.

These impenetrable swamps gave security to the position of the balloon. It was necessary to watch only the borders of the lake. The vast stretch of water broadened away from the spot, especially toward the east, and nothing could be seen on the horizon, neither mainland nor islands.

The two friends had not yet ventured to speak of their recent companion. Kennedy first imparted his conjectures to the doctor.

"Perhaps Joe is not lost after all," he said. "He was a skilful lad, and had few equals as a swimmer. He would find no difficulty in swimming across the Firth of Forth at Edinburgh. We shall see him again--but how and where I know not. Let us omit nothing on our part to give him the chance of rejoining us."

"May God grant it as you say, Dick!" replied the doctor, with much emotion. "We shall do everything in the world to find our lost friend again. Let us, in the first place, see where we are. But, above all things, let us rid the Victoria of this outside covering, which is of no further use. That will relieve us of six hundred and fifty pounds, a weight not to be despised--and the end is worth the trouble!"

The doctor and Kennedy went to work at once, but they encountered great difficulty.