Before the author prepared the preceding volume of this series, The Young Wireless Operator—With the Oyster Fleet, he first went to the Delaware Bay and made a cruise on an oyster boat, living aboard with the crew and sharing their life and labors. Furthermore, he had lived for twenty years in that country and had spent many weeks, in all, cruising about on oyster boats.

The writing of The Young Wireless Operator—Afloat, which deals with both New York City and ports on the Mexican Gulf was made possible by residence for some months on the Gulf, and through the coöperation of Southern newspaper men. Practically all the incidents related concerning the tidal wave that destroyed Corpus Christi are stories of actual occurrences, gathered by newspaper men on the spot. Most of the ships described in that story are real vessels and were actually afloat at the time and in the positions given to them by the author. The wireless stations and wireless calls are also real.

Before writing The Young Wireless Operator—As a Fire Patrol, the writer spent many days in the forest with a District Forester, studying the actual working of the Pennsylvania State Forestry system, though in earlier years he had spent weeks camping and tramping in those same mountain forests. Many of the incidents used in the book were contributed by forest rangers. The manuscript of the book was read and approved by both the District Forester and Gifford Pinchot, then Pennsylvania Commissioner of Forestry and now Governor of Pennsylvania, in order that there might be no mistakes in the text. Mr. Pinchot also showed his approval of the book by writing a foreword for it.

This present wireless series really had its inception, years ago, with the appearance of In Camp at Fort Brady. Readers of that book showed so much interest in some of the characters that, when it came to writing further volumes, the author naturally went on with the history of some of those boys. Thus Roy Mercer and Alec Cunningham and Charley Russell and Willie Brown, who have figured in The Young Wireless Operator series, are really old acquaintances, and made their first appearance in In Camp at Fort Brady, and their next in The Secret Wireless and in The Hidden Aerial. The later volumes have dealt with individual members of the Camp Brady Wireless Patrol rather than with the Patrol as a whole. The author has become as much interested in this band of boys as he hopes any of his readers has. And it is his plan to go on with these individual histories until we know what became of each boy.

Lewis Edwin Theiss.

Otzinachson, Muncy, Pa.

January 29, 1923.

CONTENTS
I.[An Unexpected Opportunity]
II.[An Adventure with a Secret Service Man]
III.[A Tip by Wireless]
IV.[The Capture of the Wool Smugglers]
V.[On the Trail of a Cotton Thief]
VI.[What Was Behind the False Partition]
VII.[Willie Gets His Chance]
VIII.[In the Armenian Quarter]
IX.[Under a Cloud]
X.[The Cloud Grows Darker]
XI.[Willie Makes a Discovery]
XII.[The Mystery of the Wheat Sacks]
XIII.[Saved by Wireless]
XIV.[Who Made the False Key?]
XV.[A Watch on a Diamond Smuggler]
XVI.[Where the Jewels Were Hidden]
XVII.[After the Whiskey Smugglers]
XVIII.[The Pursuit in the Dark]
XIX.[Victory]

The Young Wireless Operator—

With the U.S. Secret Service