test tube was the
end of the experiment. Success was now again on the side of Tom Swift.

But when that has been said there remains the fact that it was just the
other way with the unfortunate Mr. Baxter.

Try as he had, he could not succeed in getting the right chemical
combination to perfect the dye process imparted to him by his late
French friend. With the disappearance of the secret formulae went the
good luck of Josephus Baxter.

He had worked hard, taking advantage of Tom's generosity, to bring back
to his memory the proper manner of mixing certain ingredients, so that
permanent dyes of wondrous beauty in coloring would be evolved. But it
was all in vain.

"I know who have those formulae," declared the chemist again and again.
"It is those scoundrels, Field and Melling. And they are planning to
build up their own dye business with what is mine by right!"

And though Tom, also, believed this, there was no way of proving it.

As the young inventor had said, he was now ready to put his own latest
invention on the market. After many tests, aided in some by Mr. Baxter,
a form of liquid fire extinguisher had been made that was superior to
any known, and much cheaper to manufacture. Veteran members of fire
departments in and about Shopton told Tom so. All that remained was to
demonstrate that it would be as effective on a large scale as it was on
a small one, and big cities, it was agreed, must, of necessity, add it
to their equipment.

"Well, I think I'll give orders to start the works going," said Tom, at
the conclusion of the final test. "I have all the ingredients on hand
now, and all that remains is to combine them. My airship is all ready,
with the bomb-dropping device."

"And I wish you all sorts of luck," said Mr. Baxter. "Now I am going to
have another go at my troubles. I have just thought of a possible new
way of combining two of the chemicals I need to use. It may be I shall
have success."

"I hope so," murmured Tom. He was about to leave the room when Koku,
the giant, entered, with a letter in his hand. The big man showed some
signs of agitation, and Tom was at once apprehensive about Eradicate.

"Is Rad--has anything happened--shall I get the doctor?"

"Oh, Rad, him all right," answered Koku. "That is him not see yet, but
mebby soon. Only I have to chase boy, an' he make faces at me--boy
bring this," and the giant held out the envelope.

"Oh!" exclaimed Tom, and he understood now. Messeng