moment later had hit it a glancing blow, smashing the forward
propeller, and breaking off both blades. The nose of the aluminum gas
container knocked off a few bricks from the tower, and then, the ship
losing way, slowly settled to the flat roof of the building.

"We're smashed!" cried Tom, with something like despair in his voice.

"That's nothing! Don't worry! It might be worse! Not the first time
I've had an accident. It's only one propeller, and I can easily make
another," said Mr. Sharp, in his quick, jerky sentences. He had allowed
some of the gas to escape from the container, making the ship less
buoyant, so that it remained on the roof.

The aeronaut and Tom looked from the windows of the car, to note if any
further damage had been done. They were just congratulating themselves
that the rudder marked the extent, when, from a scuttle in the roof
there came a procession of young ladies, led by an elderly matron,
wearing spectacles and having a very determined, bristling air.

"Well, I must say, this is a very unceremonious proceeding!" exclaimed
the spectacled woman. "Pray, gentlemen, to what are we indebted for
this honor?"

"It was an accident, ma'am," replied Mr. Sharp, removing his hat, and
bowing. "A mere accident!"

"Humph! I suppose it was an accident that the tower of this building
was damaged, if not absolutely loosened at the foundations. You will
have to pay the damages!" Then turning, and seeing about two score of
young ladies behind her on the flat roof, each young lady eying with
astonishment, not unmixed with admiration, the airship, the elderly one
added: "Pupils! To your rooms at once! How dare you leave without
permission?"

"Oh, Miss Perkman!" exclaimed a voice, at the sound of which Tom
started. "Mayn't we see the airship? It will be useful in our natural
philosophy study!"

Tom looked at the young lady who had spoken. "Mary Nestor!" he
exclaimed.

"Tom--I mean Mr. Swift!" she rejoined. "How in the world did you get
here?"

"I was going to ask you the same question," retorted the lad. "We flew
here."

"Young ladies! Silence!" cried Miss Perkman, who was evidently the
principal of the school. "The idea of any one of you daring to speak to
these--these persons--without my permission, and without an
introduction! I shall make them pay heavily for damaging my seminary,"
she added, as she strode toward Mr. Sharp, who, by this time, was out
of the car. "To your rooms at once!" Miss P