Ordinary precaution and plenty of time should be used in the work. It is obvious that if a large coil is to be made, it is well to insure its successful completion by painstaking care and the use of proper materials. Neither is it wise to strain an instrument through becoming impatient and using it before it is properly completed and adjusted.
Wherever possible instructions have been given regarding the adjustment of the apparatus, but it is only by actual practice that the operator will acquaint himself with the most efficient manipulation.
Extracts from articles contributed by the Author to Popular Electricity have been used in the chapters on Spark Gaps, Oscillation Detectors and Telephone Receivers, through the courtesy of the editor, Mr. H. W. Young.
In conclusion, the writer wishes to express his thanks to the United Wireless Telegraph Company for views of their apparatus and to the other firms who have loaned electrotypes and supplied information. To those who have assisted in the preparation of the book, more especially to Mr. Safford Adams, for numerous suggestions and criticisms, the Author desires to express his full acknowledgments.
ALFRED POWELL MORGAN.
UPPER MONTCLAIR, N.J.
June, 1910.
PREFACE TO THE THIRD EDITION.
The success of the previous editions of this book has made a new and third one necessary.
There have not been any startling changes or new discoveries made in the field of wireless telegraphy since the first edition was published, but the art has undergone a number of small changes and improvements which have increased the efficiency and selectivity of the apparatus.