Chapter

 1 VII  |   which are simply screws with vertical axes.~2. Ornithopters, machines
 2 VII  |       of its axis. Is the axis vertical? Then it moves vertically.
 3 VII  |     the deck rose thirty-seven vertical axes, fifteen along each
 4 VII  |     screws as they rose on the vertical column of air retained their
 5 VIII |        added an equal power of vertical movement—in a word, if,
 6 X    |        Giant, spurting forth a vertical torrent twenty feet round
 7 XVIII|       the needle made with the vertical, he exclaimed: “the South
 8 XIX  |       more and more out of the vertical. There would be no difficulty
 9 XX   |     for the fore propeller was vertical in the air and still working!~
10 XXII |         went up in a perfectly vertical line—a proof of the calmness
11 XXII | pumping, had provided for this vertical motion. Without throwing
12 XXIII|     she sought her safety in a vertical direction, not dropping