"I don't exactly know," was the answer. "It's quite a little run
from Shopton, because I can't get a through train. But I think I'll
start tomorrow."

"Why do you go by train?" asked Mr. Jackson.

"Why--er--because--" was Tom's rather hesitating reply. "How else
would I go?"

"Your monoplane would be a good deal quicker, and you wouldn't have
to change cars," said the engineer. "That is if you don't want to
take out the big airship. Why don't you go in the monoplane?"

"By Jove! I believe I will!" exclaimed Tom. "I never thought of
that, though it's a wonder I didn't. I'll not take the RED CLOUD, as
she's too hard to handle alone. But the BUTTERFLY will be just the
thing," and Tom looked over to where a new monoplane rested on the
three bicycle wheels which formed part of its landing frame. "I
haven't had it out since I mended the left wing tip," he went on,
"and it will also be a good chance to test my new rudder. I believe
I WILL go to Philadelphia by the BUTTERFLY."

"Well, as long as that's settled, suppose you give us your views on
this new form of storage battery," suggested Mr. Swift, with a fond
glance at his son, for Tom's opinion was considered valuable in
matters electrical, as those of you, who have read the previous
books in this series, well know.

The little group in the machine shop was soon deep in the discussion