This is a print on demand publication. A study of the inventor Reginald A. Fessenden who was born in 1866 in Canada. Although the core of his more public fame rests on his seminal contributions to wireless, the more than 200 patents he was granted cover an amazing range. In addition, Fessenden developed the concept of what is today termed amplitude modulated (AM) radio. He produced and improved upon equipment to demonstrate the principles involved, being the first individual to transmit voice and music over the air. He was the first to establish consistent two—way wireless commun. across the Atlantic Ocean. In the course of his wireless work, he was granted a patent for use of the heterodyne principle that became so important in the vacuum tube era of radio and beyond. Illus.