. This could be done without stopping the
motor.

"I wonder if it was the fire Grit was anticipating all the while he
acted so queer?" asked Innis.

"I don't know--but it was something," Dick said. "I shouldn't wonder
but what he did have some premonition of it. Anyhow, you gave the
alarm in time, old boy!" and he patted his pet on the back.

Grit waved his tail, and barked. He seemed himself again.

It took some time to make good the damage done by the fire, and it was
accomplished as the airship was put back on her course again, and sent
forward toward the Pacific coast. They were all congratulating
themselves on their narrow escape from possible failure.

It was that same afternoon, when Mr. Vardon had finished his task, that
something else happened to cause them much wonderment.

The motor was again in almost perfect condition, and was running well.
Most of the party were out on the deck behind the cabin, enjoying the
air, for the day had been hot, and they were tired from fighting the
tire.

Suddenly Grit, who was in the pilot-house with Dick, ran out into the
main cabin, and, looking from one of the windows, which he could do by
jumping up in a chair, he began to bark violently.

"Well, what's the matter now?" demanded Dick. "Is it another fire?"

Grit barked so persistently that Dick called to Paul:

"See what ails him; will you? He must have caught sight of something
out of the window."

"I should say he had!" yelled Paul, a moment later. "Here's a rival
airship after us, Dick!"

CHAPTER XXX

AN ATTACK

Paul's announcement created considerable excitement. Though they had
covered a large part of their trip, the young aviators had not yet seen
any of their competitors. As a matter of fact, Dick's craft was among
the first to get away in the trans-continental race. But he had feared,
several times, that he might be overtaken by lighter and speedier
machines.

Now, it seemed, his fears were about to be realized. For the big
biplane that Grit had first spied, could be none other than one of
those engaged in a try for the twenty-thousand-dollar prize. They were
now nearing the Rockies, and it was not likely that any lone aviator
would be flying in that locality unless he were after the government
money.

"Another airship; eh?" cried Dick. "Let me get a look at her! Someone
take the wheel, please."

"I'll relieve you," offered Lieutenant McBride, whose official duties
allowed hi