the _Spider_, the girls were
interested enough to come down to look at it.

"All aboard!" cried Will, who was quite proud of his apparatus. "Come
on, girls!"

"Wait until we see you try it," suggested Betty.

"Well, then, get in, fellows!"

Allen, Frank and Mr. Blackford took their places, Allen to steer while
Will looked after the motor. Looking to see that all was running
smoothly, the big notched wheel at the stern revolving swiftly, Will
cautiously lowered it. There was a shower of icy particles as the teeth
chipped into the frozen surface of the river, and then the _Spider_
slowly forged ahead, under the influence of the motor instead of a sail.

"Oh, they're actually moving!" cried Grace.

"And how fast!" agreed Mollie.

"That's fine!" declared Betty.

"I--I'm going to ask them to give me a ride!" exclaimed Amy. "Oh, it
must be glorious!"

"Well, if she's brave enough to risk it, I am!" said Grace positively.
"Shall we go, girls?"

"Wait a bit and see what happens," suggested Mollie. But nothing seemed
to be going to happen. On up the river went the auto ice boat at
ever-increasing speed.

CHAPTER XIX

MAROONED

"Dare we take it out ourselves?" asked Grace.

"I don't see why not," replied Mollie. "I can run a motor car, Betty can
manage a motor boat, and this is sort of between them both. Of course we
can run it!"

"Will you promise to go slow?" asked Amy, timidly.

"Of course," agreed Betty. "Anyhow the ice is so soft that we can't get
as much speed out of it as the boys did the other day."

The outdoor girls were grouped about the auto ice boat at the little
dock near their cabin. The boys had gone off on a hunt, a rumor of a
bear having been seen about five miles off coming to them by a friendly
lumberman.

The girls were discussing the advisability of going out for a little
trip in the queer craft that Will and his chums had made. For a week
past the boys had run it at various times, taking the girls out on
trips, and explaining how the motor and notched wheel operated. The
girls had even run it for short distances themselves, under the
tutelage of the boys.

A week has passed since it was first run and, though it was voted "great
sport," the boys had rather tired of it, especially when the rumor of
the bear reached them.

"Will said we could take it whenever we wanted to," spoke Grace, as she
arranged some fur rugs in the cockpit. "But are you sure you can run it,
Mollie--