Half an hour later, the party, accoutred in their diving armour--between which and their ordinary clothing they had interposed stout warm flannel overalls--and armed with small ice-hatchets, mustered in the pilot- house; the ship was released from the ground, a vacuum created in her air-chambers, and upward she at once shot into the clear blue cloudless sky. A few minutes only sufficed her to soar to the height of ten thousand feet, after which her progress upward, as indicated by the steadily falling column of mercury in the tube of the barometer, gradually decreased in velocity. At the height of twenty-nine thousand feet the mercury ceased to fall, or the ship ceased to rise, which amounted to the same thing, and Mount Everest lay before them, its snowy peak glistening in the sun ten miles away, and its topmost pinnacle still towering somewhere about five hundred feet above the line of their horizon. "Well," said the professor, remarking upon their failure to attain a greater altitude, "I anticipated this; I was quite prepared to find that here, where the sun is so much more nearly vertical than it is with us in England, we should meet with a more rarefied atmosphere. However, we cannot help it. We must do what we can; and if we fail to reach the summit we shall simply be obliged to descend again, rid ourselves temporarily of a few of our more weighty matters, and then renew the attempt. Perhaps we may be enabled to _force_ her up that remaining five hundred feet by the power of her engines. Let us try."