ments for a one-man control in releasing the
chemical containers into the heart of a big blaze.

Tom Swift owned several airships, and he finally selected one of not
too great size, but very powerful, that would hold three and, if
necessary, four persons. This was rebuilt to enable a considerable
quantity of the fire-extinguishing liquid to be stored in the under
part of the somewhat limited cockpit.

This much done, and while his men were making up a quantity of the
extinguisher, using the secret formula, and storing it in suitable
containers, Tom began attaching a searchlight to his "cloud
fire-engine," as Koku called it.

The giant was aching to be with Tom and help in the new work, but Koku
was faithful to the blinded Eradicate, and remained almost constantly
with the old colored man.

It was touching to see the two together, the giant trying, in his kind,
but imperfect way, to anticipate the wishes of the other, with whom he
had so often disputed and quarreled in days past. Now all that was
forgotten, and Koku gave up being with Tom to wait on Eradicate.

While the colored man was, in fact, unable to see, following the
accident when Tom was experimenting with the fire extinguisher, it was
hoped that sight might be restored to one eye after an operation. This
operation had to be postponed until the eyes and wounds in the face
were sufficiently healed.

Meanwhile Rad suffered as patiently as possible, and Koku shared his
loneliness in the sick room. Tom came to see Rad as often as he could,
and did everything possible to make his aged servant's lot happier. But
Rad wanted to be up and about, and it was pathetic to hear him ask
about the little tasks he had been wont to perform in the past.

Rad was delighted to hear of Tom's success with the new apparatus,
after having been told how quickly the barn fire was put out.

"Yo'--yo' jest wait twell I gits up, Massa Tom," said Rad. "Den Ah'll
help make all de contraptions on de airship."

"All right, Rad, there'll be plenty for you to do when the time comes,"
said the inventor. And he could not help a feeling of sadness as he
left the colored man's room.

"I wonder if he is doomed to be blind the rest of his life," thought
Tom. "I hope not, for if he does it will be my fault for letting him
try to mix those chemicals."

But, hoping for the best, Tom plunged into the work ahead of him. He
did not want to offer his aerial fire extinguisher to any large city
unt