Senor Oje arose and lit a fresh black cigar.
"It will be well for you and Major Honeywell to talk over these things while I see my Chicago banker," said he. And with a good-natured "Adios, Senores," he left the apartment.
"Now, about this liquid hydrogen?" began Major Honeywell at once.
"Well," said Ned, "instead of ballast, I'm going to carry reserve hydrogen with me."
"And is that so difficult?" asked the Major.
"Impossible, if you try to carry material to make the gas," answered the boy.
"And so you are going to carry it in liquid form?"
"I'm going to try, although the making of liquid hydrogen is, so far, pretty much a theory. It has been made only under tremendous pressure and at minus 423 degrees Fahrenheit."
The Major whistled.
"That is so cold that ice is red hot comparatively," explained Ned. "This work must be done, in Washington."