can't, that's all."

By this time they had reached the road and Mollie went straight to the
car. While she and Betty were trying to find out what was wrong the other
two girls and Professor Dempsey looked on anxiously.

"Well, as far as I can see there is absolutely nothing wrong with it,"
snapped Mollie at last, lifting a face flushed with exertion. "Get in,
girls, and I'll start the engine--or try to. Then if she won't go we'll
have to make up our minds to stay here all night or walk to the next
garage."

Accordingly the girls got in and Mollie pressed the self-starter. To her
great surprise, the engine purred a response, and as she shifted her gears
the car moved slowly forward.

"Oh, goodie, we're going," cried Amy, and the faces of the other girls
showed relief.

"Must have been a drop of water in the gasoline," hazarded Mollie, and
then she throttled the engine once more while she and her chums turned to
say good-bye to Professor Dempsey. The latter was still standing in the
road, looking up at them rather wistfully.

"I'm glad that I had an opportunity of helping you, young ladies--very
glad," he answered, in response to their repeated thanks. "You conferred a
great favor on me also, for I have little company. Good-bye--and good luck
to you."

The girls responded gayly, and as they started forward Betty leaned far