Reginald Fessenden
Reginald Aubrey Fessenden (October 6, 1866 – July 22, 1932) was a Canadian-born inventor, who did a majority of his work in the United States and also claimed U.S. citizenship through his American-born father. During his life he received hundreds of patents in various fields, most notably ones related to radio and sonar.
Ranulph Fiennes
Fiennes served in the British Army for eight years including a period on counter-insurgency service while attached to the Army of the Sultanate of Oman. He later undertook numerous expeditions and was the first person to visit both the North and South Poles by surface means and the first to completely cross Antarctica on foot. In May 2009, at the age of 65, he climbed to the summit of Mount Everest. According to the "Guinness Book of World Records" in 1984, he was the world's greatest living explorer. Fiennes has written numerous books about his army service and his expeditions as well as a book defending Robert Falcon Scott from modern revisionists.