Balloons of War

    

This week in class I studied the American Civil War, where we see the first official military use of aerial reconnaissance in the United States.  Obviously there weren't airplanes yet, so what did they use? Balloons!  Although now the novelty and sport of balloons makes this idea funny (for me at least), balloon reconnaissance was a dangerous field.  The hydrogen gas used to fill the balloons was highly flammable, and before the balloon ascended high enough, it's occupants were very susceptible to gunfire.  Also, being in the air was a new and scary thing for most people. In class on Wednesday, my fellow student Moe told the class that as balloons started to be implemented in the Union, prisoners were forced to go up in the balloons because everyone else was too afraid to try it.  One of the most famous aeronauts of the war was Thaddeus Lowe, a balloon enthusiast who actually set up a demonstration of his balloon in Washington to convince the military to take it on.  From perhaps his most notable balloon flight Lowe gathered intelligence that led to the Battle of Gettysburg: he saw that the fort at Yorktown was being evacuated.

    

 

One of Lowe's balloons, the Intrepid

http://www.old-picture.com/pics/civil-war/005/replenishing-CONSTITUTION-Professor-INTREPID.htm

Apart from studying the history of military balloons in class, each student had to pick a connected subject that interested them and independently research that.  I decided to look more into the use of cryptography in the US Civil War.  I just recently saw "The Imitation Game" (with one of my favorite actors EVER Benedict Cumberbatch), which follows the story of Alan Turing and his team breaking the Nazi code "Enigma" in WWII.  We've come a long way since then, and I comparatively wanted to see how far we'd come by the 1940s from the 1860s.  During the Civil War, the Caesar cipher, also known as the Vigenére cipher was widely used by both sides.  First seen in 1553, the Caesar cipher lines up two alphabets where each letter signifies another.  A code word at the beginning of a message would prompt the reader where to set their alphabet.

 A Confederate Vigenére cipher
http://www.cryptomuseum.com/crypto/vigenere/

 Although historians aren't sure how much either side cracked the code of the other, we now know how to crack the cipher quite easily.  William Friedman (1891-1969) created a statistical analysis of the cipher called the "Index of coincidence."  Basically, the letter "e" is the most common in the English language, happening at a frequency of .127, so it is most likely that the highest repeated letter in a message is an e.  From there, one can find out the whole cipher.  Although now the Caesar cipher is considered one of the most easily broken codes, it was once thought to be unbreakable.  The same was true for the "Enigma" machine in WWII.  It's funny how everyone thinks that something is impossible until someone beats it!

 Bibliography:
Glassford, W A. "The Balloon in the Civil War." Journal of the Military Service Intitution of the United States 18 (1896).

Lowe, T. (1911). The Balloons with the Army of the Potomac. The Photographic History of the Civil War, 8.

Reuvers, P., & Simons, M. (2014, May 15). Vigenère Cipher. In Crypto Mueseum.