all hands have been piped to quarters, so we'll start. It's nearly
four bells, and I told the mate I'd be there by then. Let's start."

And start they did. On the way toward the river, whither Mr. Marlin
insisted on leading the girls, Betty explained how her uncle had
arrived unexpectedly that day, and had talked mysteriously about the
surprise.

"It's a boat-- I'm sure it is," said Mollie.

"Oh, he'd talk that same way about an automobile or an airship," said
Betty. "He calls everything, 'she,' and if it was an auto he'd
'anchor' it near the river just to be close to the water he loves so
much."

"What if it's an airship?" asked Amy.

"I shall-- learn to run it!" declared Betty.

"Never!"

"Yes I shall."

"Let us hope it is but a rowboat then," sighed Amy.

They went out on the public dock in the Argono River. At the string
piece was tied what the girls saw was one of the neatest motor boats
that, as Will said afterward, "ever ate a gasoline sandwich."

There was a trunk cabin, an ample cockpit at the stern, a little