to say," stammered Tom.

But he was saved the necessity for just then several women, evidently
other teachers, came out on the roof.

"Oh, an airship!" exclaimed one. "How lovely! We thought it was an
earthquake, and we were afraid to come up for quite a while. But an
airship! I've always wanted to see one, and now I have an opportunity.
It will be just the thing for my physical geography and natural history
class. Young ladies, attention, and I will explain certain things to
you."

"Miss Delafield, do you understand enough about an airship to lecture
on one?" asked Miss Perkman smartly.

"Enough so that my class may benefit," answered the other teacher, who
was quite pretty.

"Ahem! That is sufficient, and a different matter," conceded Miss
Perkman. "Young ladies, give your undivided attention to Miss
Delafield, and I trust you will profit by what she tells you.
Meanwhile I wish to have some conversation concerning damages with the
persons who so unceremoniously visited us. It is a shame that the
pupils of the Rocksmond Seminary should be disturbed at their studies.
Sir, I wish to talk with you," and the principal pointed a long,
straight finger at Mr. Sharp.

"Young ladies, attention!" called Miss Delafield. "You will observe the
large red body at the top, that is--"

"I'd rather have you explain it," whispered Mary Nestor to Tom. "Come
on, slip around to the other side. May I bring a few of my friends with
me? I can't bear Miss Delafield. She thinks she knows everything. She
won't see us if we slip around."

"I shall be delighted," replied Tom, "only I fear I may have to help
Mr. Sharp out of this trouble."

"Don't worry about me, Tom," said the balloonist, who overheard him.
"Let me do the explaining. I'm an old hand at it. Been in trouble
before. Many a time I've had to pay damages for coming down in a
farmer's corn field. I'll attend to the lady principal, and you can
explain things to the young ones," and, with a wink, the jolly aeronaut
stepped over to where Miss Perkman, in spite of her prejudice against
the airship, was observing it curiously.

Glad to have the chance to talk to his young lady friend, Tom slipped
to the opposite side of the car with her and a few of her intimate
friends, to whom she slyly beckoned. There Tom told how the Red Cloud
came to be built, and of his first trip in the air, while, on the
opposite side, Miss Delafield lectured to the entire school on
aeronautics, as she