While he was speaking the Ariel had risen from the ground, and was hanging a few hundred feet above the little plateau. He gave the signal for the wheels to be lowered, and the propellers to set to work at half-speed. Then he pulled the lever which moved the air-planes, and the vessel sped away forwards and upwards at about sixty miles an hour.
Arnold headed her away from the mountains until he had got an offing of a couple of miles, and then he swung her round and skirted the cliffs, rising ever higher and higher, and keeping a sharp look-out for a depression among the ridges that still towered nearly three thousand feet above them.
When he had explored some twenty miles of the mountain wall, Arnold suddenly pointed towards it, and said—
"There is a place that I think will do. Look yonder, between those two high peaks away to the southward. That ridge is not more than six thousand feet from the earth, and the Ariel can leap that as easily as an Irish hunter would take a five-barred gate."
"It looks dreadfully high from here," said Natasha, in spite of herself turning a shade paler at the idea of taking a six thousand foot ridge at a flying leap. She had splendid nerves, but this was her first aërial voyage, and it was also the first time that she had ever been brought so closely face to face with the awful grandeur of Nature in her own secret and solitary places.
She would have faced a levelled rifle without flinching, but as she looked at that frowning mass of rocks towering up into the sky, and then down into the fearful depths below, where huge trees looked like tiny shrubs, and vast forests like black patches of heather on the earth, her heart stood still in her breast when she thought of the frightful fate that would overwhelm the Ariel and her crew should she fail to rise high enough to clear the ridge, or if anything went wrong with her machinery at the critical moment.
"Are you sure you can do it?" she asked almost involuntarily.
"Perfectly sure," replied Arnold quietly, "otherwise I should not attempt it with you on board. The Ariel contains enough explosives to reduce her and us to dust and ashes, and if we hit that ridge going over, she would go off like a dynamite shell. No, I know what she can do, and you need not have the slightest fear!"
"I am not exactly afraid, but it looks a fearful thing to attempt."
"If there were any danger I should tell you—with my usual lack of dissimulation. But really there is none, and all you have to do is to hold tight when I tell you, and keep your eyes open for the first glimpse of Aeria."