As we approached the houseboat I looked her over carefully.  One of the first things I noticed was that there rose from the roof the primitive inverted V aerial of a wireless telegraph.  I thought immediately of the unfinished letter and its contents, and shaded my eyes as I took a good look at the powerful transatlantic station on the spit of sand perhaps three or four miles distant, with its tall steel masts of the latest inverted L type and the cluster of little houses below, in which the operators and the plant were.

Waldon noticed what I was looking at, and remarked, “It’s a wonderful station—­and well worth a visit, if you have the time—­ one of the most powerful on the coast, I understand.”

“How did the Lucie come to be equipped with wireless?” asked Craig quickly.  “It’s a little unusual for a private boat.”

“Mr. Edwards had it done when she was built,” explained Waldon.  “His idea was to use it to keep in touch with the stock market on trips.”

“And it has proved effective?” asked Craig.

“Oh, yes—­that is, it was all right last winter when he went on a short cruise down in Florida.  This summer he hasn’t been on the boat long enough to use it much.”

“Who operates it?”

“He used to hire a licensed operator, although I believe the engineer, Pedersen, understands the thing pretty well and could use it if necessary.”

“Do you think it was Pedersen who used it for Mrs. Edwards?” asked Kennedy.

“I really don’t know,” confessed Waldon.  “Pedersen denies absolutely that he has touched the thing for weeks.  I want you to quiz him.  I wasn’t able to get him to admit a thing.”

CHAPTER VIII

THE HOUSEBOAT MYSTERY

We had by this time swung around to the side of the houseboat.  I realized as we mounted the ladder that the marine gasoline engine had materially changed the old-time houseboat from a mere scow or barge with a low flat house on it, moored in a bay or river, and only with difficulty and expense towed from one place to another.  Now the houseboat was really a fair-sized yacht.

The Lucie was built high in order to give plenty of accommodation for the living quarters.  The staterooms, dining rooms and saloon were really rooms, with seven or eight feet of head room, and furnished just as one would find in a tasteful and expensive house.

Down in the hull, of course, was the gasoline motor which drove the propeller, so that when the owner wanted a change of scene all that was necessary was to get up anchor, start the motor and navigate the yacht-houseboat to some other harbor.

Edwards himself met us on the deck.  He was a tall man, with a red face, a man of action, of outdoor life, apparently a hard worker and a hard player.  It was quite evident that he had been waiting for the return of Waldon anxiously.

“You find us considerably upset, Professor Kennedy,” he greeted Craig, as his brother-in-law introduced us.