"A hail storm!" echoed Mr. Parker. "I expected we would have one. The hailstones will become even larger than this!"
"Cheerful," remarked Tom in a low voice, with an apprehensive look at Ned.
"Is there any danger?" asked his chum.
"Danger? Plenty of it," replied the young inventor. "The frozen particles may rip open the gas bag." He stopped suddenly and looked at a gage on the wall of the steering-tower—a gage that showed the gas pressure.
"One compartment of the bag has been ripped open!" cried Tom. "The vapor is escaping! The whole bag may soon be torn apart!"
The noise of the pelting hailstones increased. The roar of the storm, the bombardment of the icy globules, and the moaning of the wind struck terror to the hearts of the gold-seekers.
"What's to be done?" yelled Ned.
"We must go up, to get above the storm, or else descend and find some shelter!" answered Tom. "I'll first see if I can send the ship above the clouds!"
He increased the speed of the motor so that the propellers would aid in taking the ship higher up, while the gas-generating machine was set in operation to pour the lifting vapor into the big bag.
