The voyage across Africa progressed pleasantly and almost uneventfully for the thirty-six hours after the crossing of the Red Sea. After passing over the mountains of the coast, the Ariel had travelled at a uniform height of about 3000 feet over a magnificent country of hill and valley, forest and prairie, occasionally being obliged to rise another thousand feet or so to cross some of the ridges of mountain chains which rose into peaks and mountain knots, some of which touched the snow-line.
Several times the air-ship was sighted by the people of the various countries over which she passed, and crowds swarmed out of the villages and towns, gesticulating wildly, and firing guns and beating drums to scare the flying demon away.
Once or twice they heard bullets singing through the air, but of these they took little heed, beyond quickening the speed of the air-ship for the time, knowing that there was not a chance in a hundred thousand of the Ariel being hit, and that even if she were the bullet would glance harmlessly off her smooth hull of hardened aluminium.
Once only they descended in a delightful little valley among the mountains, which appeared to be totally uninhabited, and here they renewed their store of fresh water, and laid in one of fruit, as well as taking advantage of the opportunity to stretch their legs on terra firma.
This was on the Saturday morning; and when they again rose into the air to continue their voyage, they saw that they had crossed the great mountain mass that divides the Sahara from the little-known regions of Equatorial Africa, and that in front of them to the south-west lay, as far as the eye could reach, a boundless expanse of dense forest and jungle and swamp, a gloomy and forbidding-looking region which it would be well-nigh impossible to traverse on foot.
Early in the afternoon the four voyagers were gathered in the deck-saloon, closely examining a somewhat rudely-drawn chart that was spread out on the table. It was the map that formed part of the manuscript which had been found in the car of Louis Holt's miniature balloon, and sketched out his route from Zanzibar to Aeria, and the country lying round so far as he had been able to observe it.
"This gives us, after all, very little idea of the distance we have yet to go," said Arnold; "for though Holt has got his latitude presumably right, we have very little clue to his longitude, for he says himself that his watch was stopped in a thunder-storm, and that in the same storm he lost all count of the distance he had travelled. Added to that, he admits that he was blown about for twelve days in one direction and another, so that all we really know is that somewhere across this fearful wilderness beneath us we shall find Aeria, but where is still a problem."
"What is your own idea?" asked Colston.
"Not a very clear one, I must confess. At this elevation we can see about sixty miles as the atmosphere is now, and as far as we can see to the south-west there is nothing but the same kind of country that we have under us. We have travelled rather more than 2700 miles since we left the Hindu Kush, and according to my reckoning Aeria lies somewhere between 3000 and 3200 miles south-west of where we started from on Thursday morning. That means that we are within between three and five hundred miles of Aeria, unless, indeed, our calculations are wholly at fault, and at that rate, as we only have about four and a half hours' daylight left, we shall not get there to-day at our present speed."
"Couldn't we go a bit faster?" put in Natasha. "You know I and the Princess are dying to see this mysterious unknown country that only two other people have ever seen."