Parker Hitt, b. 1878, who before the war had been an Army Signal Corps instructor. He was one of the first to try to bring US Army cryptology into the 20th century, publishing an influential short work on the subject in 1915 called the Manual for the solution of military ciphers, Publication date 1916, available at https://archive.org/details/manualforsolutio00hittrich. He was assigned to France in an administrative role, but his advice was eagerly sought by colleagues working in operational cryptology. Another Signal Corps officer who would make his mark on cryptology was Joseph Mauborgne, who in 1914, as a first lieutenant, had been the first to publish a solution to the Playfair cipher. When the Americans began moving up to the front in numbers in early 1918, they adopted trench codes and became very competent at their construction, with a Captain Howard R. Barnes eventually learning to produce them at a rate that surprised British colleagues. The Americans adopted a series of codes named after rivers, beginning with "Potomac". They learned to print the codebooks on paper that burned easily and degraded quickly after a few weeks, when the codes would presumably be obsolete, while using a font that was easy to read under trench conditions. Communications discipline American code makers were often frustrated by the inability or refusal of combat units to use the codes—or worse, to use them properly. A soldier engaged in combat doesn't always feel the need to do things "by the book" even when there are very good reasons to do so, and generals on the front line felt that they had other things to worry about. Lt. Col. Frank Moorman, reviewing U.S wireless intelligence in 1920. wrote: That will be the real problem for the future, to make the men at the front realize the importance of handling codes carefully and observing "foolish" little details that the code man insists on. They cannot see the need of it and they do not want to do it. They will do anything they can to get out of it. My idea would be to hang a few of the offenders. This would not only get rid of some but would discourage the development of others. It would be a saving of lives to do it. It is a sacrifice of American lives to unnecessarily assist the enemy in the solution of our code. The British and French were