"Then the girls will find out what it is!" declared Will, with conviction. "If they could find the man who lost the five hundred dollar bill, they're equal to laying the ghost of Elm Island. I'm not going to worry about them."

"Let's go down a little way farther and have a look at the haunted island," proposed Grace, when they were again on board the Gem.

"Have we time?" asked Betty.

"Lots," declared Will.

The motor boat was headed for the place. The island was of good size, well wooded, and the sh.o.r.e was lined with bushes. There were a few bungalows on it, but the season was not very good this year, and none of them had been rented. The girls half-planned to hire one to use as headquarters in case they camped on the island.

"It doesn't look very-- ghostly," said Betty, as she surveyed it from the c.o.c.kpit of her craft.

"No, it looks lovely," said Grace.

"Is the ghost going to keep us away?" asked Mollie.

"Never!" cried the Little Captain, vigorously.

"Hurray!" shouted Will, waving the boat's flag that he took from the after-socket.

They made a turn of the island, and started back up the river for Deepdale, reaching Mollie's dock without incident.

Busy days followed, for they were getting ready for the cruise. Uncle Amos went out with Betty and the girls several times to offer advice, and he declared that they were fast becoming good sailors.

"Of course not good enough for deep water," he made haste to qualify, "but all right for a river and a lake."

The girls were learning to tell time seaman fashion. Betty fairly lived aboard her new boat, her mother complained, but the Little Captain was not selfish-- she invited many of her friends and acquaintances to take short trips with her. Among the girls she asked were Alice Jallow and Kittie Rossmore, the two who had acted rather meanly toward our friends just prior to the walking trip. But Alice was sincerely sorry for the anonymous letter she had written, giving a hint of the mystery surrounding Amy Stonington, and the girls had forgiven her.

Betty's Aunt Kate arrived. She was a middle-aged lady, but as fond of the great out-doors as the girls themselves. She was to chaperone them for a time.

The final preparations were made, the sailor suits were p.r.o.nounced quite "chicken" by Will-- he meant "chic," of course. Trunks had been packed, some provisions put aboard, and all was in readiness. Uncle Amos planned to meet the girls later, and see that all was going well.

The boys were to be given a treat some time after Rainbow Lake was reached, word to be sent to them of this event.

"All aboard!" cried Betty on the morning of the start. It was a glorious, sunshiny day, quite warm, but there was a cool breeze on the river. "All aboard!"

"Oh, I just know I've forgotten something!" declared Grace,

"Your candy?" questioned Mollie.

"No, indeed. Don't be horrid!"

"I'm not. Only I thought---- "

"I'm just tired of thinking!" returned Betty.

"Shall I cast off?" asked Will, who, with Frank, had come down to the dock to see the girls start.

"Don't you dare!" cried Mollie. "I'm sure I forgot to bring my---- "

She made a hurried search among her belongings. "No, I have it!" and she sighed in relief. She did not say what it was.

"All aboard!" cried Betty, giving three blasts on the compressed air whistle.

"Don't forget to send us word," begged Frank. "We want to join you on the lake."

"We'll remember," promised Betty, with a smile that showed her white, even teeth.

All was in readiness. Good-byes had been said to relatives and friends, and Mrs. Billette, holding Paul by the hand, had come down to the dock to bid farewell to her daughter and chums.

"Have a good time!" she wished them.

A maid hurried up to her, and said something in French.

"Oh, the doctor has come!" exclaimed Mollie's mother. "The doctor who is to look at Dodo-- the specialist. Oh, I am so glad!"

"Shall I stay, mother?" cried Mollie, making a move as though to come ash.o.r.e.

"No, dear; no! Go with your friends. I can send you word. You may call me by the telephone. Good-bye-- good-bye!"

The Gem slowly dropped down the stream under the influence of the current and her own power, Betty having throttled down the motor that the farewell calls might be better heard. Mrs. Billette, waving her hand, hastened toward the house, the maid taking care of little Paul, whose last request was:

"Brin' me some tandy!"

CHAPTER X

ADRIFT

"Well, Captain Betty, what are your orders?" asked Amy, as the four girls, and Aunt Kate, stood grouped in the s.p.a.ce aft of the trunk cabin, Betty being at the wheel, while the Gem moved slowly down the Argono River.

"Just make yourselves perfectly at home," answered Betty. "This trip is for fun and pleasure, and, as far as possible, we are to do just as we please. You don't mind; do you, Aunt Kate?"

"Not in the least, my dear, as long as you don't sink," and the chaperone smiled indulgently.

"This boat won't sink," declared Betty, with confidence. "It has water-tight compartments. Uncle Amos had them built purposely."

"It certainly is a beautiful boat-- beautiful," murmured Mollie, looking about as she pulled and straightened her middy blouse. "And it was so good of you, Bet, to ask us on this cruise."

"Why, that's what the boat is for-- for one's friends. We are all shipmates now."

"'Strike up a song, here comes a sailor,'" chanted Grace, rather indistinctly, for she was, as usual, eating a chocolate.

The girls, standing there on the little depressed deck, their hair tastefully arranged, topped by natty little caps, with their sailor suits of blue and white, presented a picture that more than one turned to look at. The Gem was near the sh.o.r.e, along which ran a main-traveled highway, and there seemed to be plenty of traffic this morning. Also, a number of boats were going up or down stream, some large, some small, and often the occupants turned to take a second look at the Outdoor Girls.

Certainly they had every appearance of living the life of the open, for they had been well tanned by the long walk they took, and that "berry-brown" was being added to now by the summer sun reflecting from the river.

"Is this as fast as you can go?" asked Mollie, as she looked over the side and noted that they were not much exceeding the current of the river.

"Indeed, no! Look!" cried Betty, as she released the throttle control that connected the gasoline supply with the motor. At once, as when the accelerator pedal of an auto is pressed, the engine hummed and throbbed, and a ma.s.s of foam appeared at the stern to show the presence of the whirling propeller.

"That's fine!" cried Grace, as Betty slowed down once more.