by his error in
predicting.

"I am sure that what I heard was a tremor, due to some distant
earthquake shock," he said. "The mule's kicking was only a coincidence."

And Tom let him have his way about it. The week was drawing to a close,
and the Red Cloud was nearly in shape for the voyage. At almost the
last minute Tom found that he needed some electrical apparatus for the
airship, and as he had to go to Chester for it, he decided he would make
the trip in his monoplane, and, while in the city, would also get the
diamond pin he was having made for Mary Nestor.

He started off early one morning, in the swift little craft Butterfly,
and soon had reached Chester. The diamond brooch was ready for him.

"It is one of the most beautiful stones we have ever set," the diamond
merchant told him. "Don't forget, if you find any more, Mr. Swift, to
let us have a chance to bid on them."

"I may," Tom promised, rather indefinitely. Then, having purchased his
electrical supplies, he made a quick trip to Shopton, stopping on the
way to call on Miss Nestor.

"Why Tom, I'm delighted to see you!" cried the girl, blushing prettily.
"Did you come for some apple turnovers?" and she laughed, as she
referred to a call Tom had once paid, when a new cook had been engaged,
and when the pastry formed a feature of the meal.

"No turnovers this time," said the young inventor. "I came to wish you
many happy returns of the day."

"Oh, you remembered my birthday! How nice of you!"

"And here is something else," added our hero, rather awkwardly, as he
handed her the diamond pin.

"Oh, Tom! This for me! Oh, it's too lovely--it's far too much!"

"It isn't half enough!" he declared, warmly. "Oh, what a large diamond!"
Mary cried as she saw the sparkling stone. "I never saw one so large and
beautiful!"

"It's just as easy to make them large as small," explained Tom.

"Make them?" she looked the surprise she felt.

"Yes, I'm about to start for the place where diamonds are made."

"Oh, Tom! But isn't it dangerous? I mean won't you have to go to some
far country--like Africa--to get to where diamonds are made?"

"Well, we are going on quite a trip, but not as far as that. And as
for the danger--well, we'll have to take what comes," and he told her
something of the proposed quest.

"Oh, it sounds--sounds scary!" Mary exclaimed, when she had heard of Mr.
Jenks' experience. "Do be careful, Tom!"

"I will," he promised, and, somehow he was