Happy birthday, Ferdinand von Zeppelin

It is the birthday of German army officer and manufacturer Ferdinand von Zeppelin (1838) [inset], who is credited with building the first commercially viable airship. Zeppelin's vision was a considerable departure from the hot air balloons he rode as a young officer on a trip to the United States during the Civil War. Those balloons were used as observation posts for the Union Army. Many years later, Zeppelin constructed huge, rigid dirigibles that were used for transportation. Zeppelin died in 1917, before seeing the widespread success of his invention. Zeppelin's successor, Hugo Eckener, continued Zeppelin's work and oversaw the construction of the most successful dirigible ever built, Graf Zeppelin, named for Eckener's mentor. Eckener piloted the airship on the first dirigible flight around the world in 1929, an Arctic research trip in 1931, and to the Chicago World's Fair in 1933. Eckener wrote Count Zeppelin: The Man and His Work (1938).