"Fo' de captain," exclaimed the colored boy.

"Where are you to bunk, Alan?" Ned asked, quickly.

"Oh, the crew is in the main room."

"Not much," exclaimed Ned. "We're partners in this enterprise. I don't have any better than the rest."

And in another moment he had dropped his valise alongside Alan's berth.

"We'll keep the little room for consultations," he said with a laugh, "when we don't want Elmer to hear us talking about the Indians."

The colored lad grunted.

"Can't scare me wif no Injun talk," he said. "I specs I ain't half so 'fraid o' Injuns as I is o' dat stuff in de black box."

"And it's time to attend to the 'stuff,'" interrupted Ned.

They returned to the baggage room.

"Now," Ned began, "the door to this car must be kept locked except when the train crew are compelled to come through. We, in turn, must be careful about fire and lights. But, for fear of accident, I have taken some precautions."

Alan and Elmer then saw that the top of the case was fitted with a lid the edges of which were bound with rubber. In the center of the covering was a short spout.

"What's the use of an air and gas proof top with a hole in it?"

asked Alan, inspecting it curiously.

"Maybe dat's to let de air in and de lid's to keep de hydrogum from gettin' out," volunteered the colored boy.

Ned was too busy to answer the one or to laugh at the other. He had unlocked the lid and thrown it back. About six inches beneath the top of the case stood eight iron boxes--two rows with four boxes in each. These boxes, six inches square, were each about three feet in height and in each could be seen the neck of a gla.s.s vessel.

Securely packed in their iron jackets to prevent breaking, stood the gla.s.s receptacles, open-mouthed and apparently empty. But down below the shadowed rims were soft clouds of gaseous vapor, beneath which reposed the precious contents that had cost Ned over a thousand dollars--the liquid hydrogen.

On top of the square iron buckets was coiled eight or ten feet of rubber hose. Taking it out Ned closed and locked the lid. He then screwed one end of the hose onto the open spout and, springing to the top of the case, pa.s.sed the other end out of the open ventilator.

"Now," Ned explained, "we are in less danger. Difficult as it is to condense hydrogen, it is more difficult to keep it in liquid form.

It constantly seeks to return to gas. In a closed place it might make trouble."

Elmer had already disappeared, with popping eyes and mumbles of protest. Alan proudly exhibited to his friend the results of his share of the work of preparation. Every crate, box, barrel and package was numbered and labeled and securely fastened in place.

On one side of the car stood five large oak tanks, looking like the famous beer tuns of Germany.

"I can make more hydrogen in those than you've got in your black box," Alan exclaimed jokingly.

"I'll have a better look at them in the daylight," finally said Ned; "and now those easy chairs in the other car would feel pretty good."

"Aren't sleepy, are you?" asked Alan, forgetting that his chum had not slept the night before.

"No," said Ned, "only happy. But I'd be happier if I had had time to get a good hot supper."

"All ready, sah, in de stateroom," announced Elmer's cheerful voice.

Both boys turned--Ned in surprise.

"Supper's all ready, sah!" continued the colored boy, "and waiting fo' you all."

In the stateroom was a sight to arouse a sleepy boy and to delight a hungry one. In the middle of a small table was a bunch of pink roses. On either side, in a dish of cracked ice, was the half of a luscious cantaloupe. Silver knives, forks and spoons, sparkling gla.s.s-ware and snowy napkins at once revealed the resources of the Placida's pantry.

"Well, I'll be jiggered!" exclaimed Ned.

"Pretty nifty, eh?" laughed Alan.

"Well, if this isn't the last straw!" exclaimed Ned as they seated themselves. "But I want to thank you both. I didn't know how hungry I really was--"

He was about to plunge a spoon into the fragrant, cool melon when he saw a folded note by his plate. Opening it he read:

"Dear Ned: Good luck and good voyage. The roses are from my own garden. Bring me a turquoise ring.

MARY HOPE."

It was from Alan's sister.

"Shall we do it, Alan?" he cried.

"Shall we?" answered Alan wringing his chum's hand. "We'll do it or--"

"Is you all ready for dis?" asked the young chef suddenly appearing with a smoking broiled steak. "It can't wait no longer."

And it did not have to.

An hour later the two happy boys sat on either side of the table in the drawing room of their car.

"Are you getting nervous?" began Alan.

"About what?" asked Ned.

"Oh, about everything. The responsibility for this car and the setting up of your balloon, and the trip itself."

"Are you?" exclaimed Ned.

"My, no, I'm not. But then I'm not the captain. But I thought you might be."

"Aren't we getting along all right?"

"Perhaps too well," Alan answered.

"Never talk that way," interrupted Ned decisively. "Everything is happening as it does because we planned it just that way. Things can't go too well. That is a foolish idea. The good fortune of careful preparation should only confirm your judgment."

This was the sort of advice Alan had to take now and then from his friend; but it always did him good.

"Then you don't believe in good luck?" rather sheepishly suggested Alan.