THIS BOOK, the author believes, will be of the utmost service, not only to the student and radio-electrician, but to anyone who wishes to be informed on this important field of science.
Radio equipment cannot be serviced or maintained by any predetermined set of rules or formulae, but it is necessary rather to understand the principles of elec-tricity, radio and sound.
The main object throughout has been to présent as briefly and clearly as possible a progressively arranged treatise with spécial emphasis on the fundamentals of radio, upon which ail knowledge necessarily rests.
In view of the importance of radio in the field of air and marine transportation, several chapters dealing with marine and aircraft communications as well as the principles of the automatic alarm and the radio compass have been included.
It is hoped that the numerous illustrative examples which are introduced throughout the book, may in con-junction with the data supplied, suggest proper treat-ment of practical problems in design of radio apparatus.
EDWIN P. ANDERSON
