The Capital of Bornou.--The Islands of the Biddiomahs.--The Condors.--The Doctor's Anxieties.--His Precautions.--An Attack in Mid-air.--The Balloon Covering torn.--The Fall.--Sublime Self-Sacrifice.--The Northern Coast of the Lake.

Since its arrival at Lake Tchad, the balloon had struck a current that edged it farther to the westward. A few clouds tempered the heat of the day, and, besides, a little air could be felt over this vast expanse of water; but about one o'clock, the Victoria, having slanted across this part of the lake, again advanced over the land for a space of seven or eight miles.

The doctor, who was somewhat vexed at first at this turn of his course, no longer thought of complaining when he caught sight of the city of Kouka, the capital of Bornou. He saw it for a moment, encircled by its walls of white clay, and a few rudely-constructed mosques rising clumsily above that conglomeration of houses that look like playing-dice, which form most Arab towns. In the court-yards of the private dwellings, and on the public squares, grew palms and caoutchouc-trees topped with a dome of foliage more than one hundred feet in breadth. Joe called attention to the fact that these immense parasols were in proper accordance with the intense heat of the sun, and made thereon some pious reflections which it were needless to repeat.

Kouka really consists of two distinct towns, separated by the "Dendal," a large boulevard three hundred yards wide, at that hour crowded with horsemen and foot passengers. On one side, the rich quarter stands squarely with its airy and lofty houses, laid out in regular order; on the other, is huddled together the poor quarter, a miserable collection of low hovels of a conical shape, in which a poverty-stricken multitude vegetate rather than live, since Kouka is neither a trading nor a commercial city.

Kennedy thought it looked something like Edinburgh, were that city extended on a plain, with its two distinct boroughs.

But our travellers had scarcely the time to catch even this glimpse of it, for, with the fickleness that characterizes the air-currents of this region, a contrary wind suddenly swept them some forty miles over the surface of Lake Tchad.

Then then were regaled with a new spectacle. They could count the numerous islets of the lake, inhabited by the Biddiomahs, a race of bloodthirsty and formidable pirates, who are as greatly feared when neighbors as are the Touaregs of Sahara.

These estimable people were in readiness to receive the Victoria bravely with stones and arrows, but the balloon quickly passed their islands, fluttering over them, from one to the other with butterfly motion, like a gigantic beetle.

At this moment, Joe, who was scanning the horizon, said to Kennedy:

"There, sir, as you are always thinking of good sport, yonder is just the thing for you!"

"What is it, Joe?"

"This time, the doctor will not disapprove of your shooting."

"But what is it?"

"Don't you see that flock of big birds making for us?"

"Birds?" exclaimed the doctor, snatching his spyglass.

"I see them," replied Kennedy; "there are at least a dozen of them."

"Fourteen, exactly!" said Joe.

"Heaven grant that they may be of a kind sufficiently noxious for the doctor to let me peg away at them!"

"I should not object, but I would much rather see those birds at a distance from us!"

"Why, are you afraid of those fowls?"

"They are condors, and of the largest size. Should they attack us--"

"Well, if they do, we'll defend ourselves. We have a whole arsenal at our disposal. I don't think those birds are so very formidable."

"Who can tell?" was the doctor's only remark.

Ten minutes later, the flock had come within gunshot, and were making the air ring with their hoarse cries. They came right toward the Victoria, more irritated than frightened by her presence.

"How they scream! What a noise!" said Joe.

"Perhaps they don't like to see anybody poaching in their country up in the air, or daring to fly like themselves!"

"Well, now, to tell the truth, when I take a good look at them, they are an ugly, ferocious set, and I should think them dangerous enough if they were armed with Purdy-Moore rifles," admitted Kennedy.

"They have no need of such weapons," said Ferguson, looking very grave.

The condors flew around them in wide circles, their flight growing gradually closer and closer to the balloon. They swept through the air in rapid, fantastic curves, occasionally precipitating themselves headlong with the speed of a bullet, and then breaking their line of projection by an abrupt and daring angle.

The doctor, much disquieted, resolved to ascend so as to escape this dangerous proximity. He therefore dilated the hydrogen in his balloon, and it rapidly rose.

But the condors mounted with him, apparently determined not to part company.

"They seem to mean mischief!" said the hunter, cocking his rifle.

And, in fact, they were swooping nearer, and more than one came within fifty feet of them, as if defying the fire-arms.

"By George, I'm itching to let them have it!" exclaimed ............