The name Catwhisker harked back to the days when radio, or wireless telegraphy, was in its infancy in the experience of the three boys whose adventures are the inspiration of this volume.  Mr. Perry bought the motor boat at a time when his son and the latter’s two chums were busy experimenting with crystal outfits, and the name of the cruiser was suggested to them by the fine spring-wires used to make contact with the crystals in their detectors.  No doubt, it was the catchiness of the word, as well as its association with their hobby, that appealed to them in the general search for a name for the boat.

This vessel was 36 feet long, with a beam of nine feet and with a canopy covering the after deck.  Amidships was a raised bridge deck on which were mounted and housed the wheel and engine controls.  Under this and the after deck were the engine-room and the galley, and forward 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.