Franklin var en beskeden, overvægtig,<ref>Fleming, side 126: "he was overweight and suffered from poor circulation"</ref> religiøs og meget charmerende mand.<ref>Fleming, side 126: "Franklin's charm. Everyone who met him agreed that this was his outstanding characteristic – it was impossible not to like him."</ref> Desuden var han delvist døv efter slaget ved Trafalgar.<ref>Lambert, side 26: "Trafalgar left Franklin stunned and deafened. His hearing never fully recovered, and although impaired hearing was not unusual for a career naval officer, it proved to be a serious handicap when he moved into another profession."</ref>
Videnskab