Original (inglés)

CHAPTER II MARK HANGS ON Professor Henderson and his adopted sons—Jack Darrow and Mark Sampson—had been in many perilous situations together. Neither one nor the other was likely to display panic at the present juncture, although the flying Snowbird was playing a gigantic game of "leap-frog" through the air. The professor had himself constructed many wonderful machines for transportation through the air, under the ground, and both on and beneath the sea; and in them he and his you