The speeches had been made and the toasts drunk. Tom Rider noticed that Frisco was using a bumper twice as large as the others. He said something about “Dutch courage” but not loudly enough for Frisco to hear him. By the time Frisco entered the car, he was smiling and waving merrily to the onlookers.
Peter Frigate completed the weigh-off. Until now, this had always involved making sure that the weight-envelope, gas, net, cargo chute, load ring, car, ballast, equipment, supplies, aeronauts-was slightly less than the lift. The Jules Verne was the first aerostat in which the lift-off weight was slightly more than the upward pull of the gas.
The car hanging below the bag was pumpkin shaped, and its hull was a double-walled magnesium alloy. In the center of its deck was a vertical L-shape, the vemian. Two thin plastic pipes ran from the metal contraption holes in the overhead. These were tightly packed to prevent escape of air from the car.
From there, the plastic pipes extended upward and for some distance beyond the hermetically sealed neck of the envelope. Their ends were fitted to light alloy pipes which rose to varying heights inside. One was longer than the other; both were open-ended.
The crew had been talkative before boarding. Now they looked at Frigate.
“Close the main hatch,” he said, and the lift-off ritual began.
Frigate checked a gauge and two stopcocks affixed to the vernian. He opened a little hatch on the side near the top of the L-shape. He adjusted another stopcock until he heard a slight hissing. This came from a narrow nozzle at the end of a steel pipe inside the highest compartment.
He stuck an energized electrical lighter at the end of an aluminum rod into the furnace. A tiny flame popped from the nozzle. He turned the stopcock to increase the flame, adjusted two more to regulate the mixture of oxygen and hydrogen feeding the torch. The flame began heating the base of the large platinum cone just above it.
The lower end of the longest pipe extending into the bag was fitted into the apex of the cone. As the heat was expanded in the cone, the hydrogen in it moved upward, flowing into the bag and causing it to expand. The cooler hydrogen in the lower half of the bag, aided by a suction effect, flowed into the open end of the shorter pipe inside the envelope. It went down this pipe into the side of the vemian and into the side of the cone. There it was heated and rose, completing the circuit.
One of the compartments at the base of the vernian was an electrical battery. This was far lighter and much more powerful than the battery used by Fergusson in Veme’s novel. It broke water into its elements, hydrogen and oxygen. These flowed into separate compartments, and then went to a mixing chamber, where the oxyhydrogen was piped to the torch.
One of Frigate’s modifications to Verne’s system was a pipe that led from the hydrogen storage chamber to the shorter pipe. By opening two stopcocks, the pilot could allow hydrogen from the storage chamber to flow into the balloon. This was an emergency measure used only to replace hydrogen valved off from the bag. When this was done, the torch was turned off, since hydrogen was highly inflammable.
Fifteen minutes passed. Then, with no motion noticeable, the car lifted off the ground. Frigate shut off the torch several seconds later.
The shouts of the spectators became less audible, then died out. The huge hangar shrank to a toy house. By then the sun had cleared the mountain, and the stones alongside The River thundered like artillery.
“That’s our thousand-gun salute,” Frigate said.
No one moved or spoke for a while after that. The silence was as intense as that at the bottom of a deep cave. However, the alloy walls of the hull had no sound-absorbing qualities. When Frisco’s stomach rumbled, it sounded like distant thunder.
A slight wind sprang up now, carrying the vessel southward, away from their goal. Pogaas stuck his head out of an open port. He felt no sensation of movement since the balloon traveled at the same speed as the wind. The air around the hull was as still as if he was in a sealed room. The flame of a candle set on top of the vernian would have burned straight upward.