d of these were
the cabin and two small staterooms. At the bow and in the stern were two
tall slim masts that had been erected solely for the extension of a radio
aerial. The hull was painted white with a blue stripe midway between the
bridge-deck level and the water line.

Cub and his father were real chums in matters of boating. Mr. Perry,
although ordinarily a man of very neat appearance, on the present
occasion had discarded his usual sartorial excellence and appeared on the
Catwhisker in clothes easily associated with cotton waste and oil cans.
Indeed, he could take care of the engine quite as well as his son, who
was an amateur expert, and seemed to enjoy discharging his full share, of
all the "overall and apron tasks" on board.

Mr. Perry took charge of the wheel and engine controls of the yacht at
the beginning of the cruise, so that his son and the other two boys were
left free to perfect the hook-up of the radio set supplied by Hal. First,
two wires, attached to spreaders at both ends, were extended between the
two masts for an aerial, and a lead-in was arranged through one of the
windows of the cabin. On a fixed table near this window they anchored
firmly the various portions of Hal's sending and receiving set, in order
that these might not be thrown down and damaged if the lake should become
rough. As the apparatus was supplied with two steps of amplification, Hal
had brought also a loud-tone horn to facilitate occasional parlor
entertainment should they have leisure to listen-in to programs from
various broadcasting stations within their receiving range in the course
of their cruise.

Hal's outfit was by no means as elaborate or as expensive as was Cub's,
but it was sufficient to receive radiophone programs, under favorable
conditions, from the strongest stations 300 or 400 miles distant, while
the strong spark of his code transmitter had earned for him a wide
acquaintance in amateur circles.

Before they started, Cub had another dot-and-dash tete-a-tete with "Mr.
Crusoe", acquainting the latter with the latest developments of their
plan and requesting him to call the Catwhisker regularly at half-hour
intervals if the more limited set they would take with them proved
insufficient to reach him from the start.

"When we reach the Thousand Islands, we will get busy with our loop
aerial and find you by radio compass," he promised.

The mysterious intermeddler who professed to have a sporting wager with
t