Alfred Vail and Samuel Morse collaborated in the invention of Morse code. A controversy exists over the role of each in the invention. The argument for Vail being the original inventor is laid out by several scholars.The argument offered by supporters of Morse claims that Morse originally devised a cipher code similar to that used in existing semaphore telegraphs, by which words were assigned three- or four-digit numbers and entered into a codebook. The sending operator converted words to these number groups and the receiving operator converted them back to words using this codebook. Morse spent several months compiling this code dictionary. It is said by Morse supporters that Vail, in public and private writings, never claimed the code for himself. According to one researcher, in a February 1838 letter to his father, Judge Stephen Vail, Alfred wrote, “Professor Morse has invented a new plan of an alphabet, and has thrown aside the Dictionaries.” In an 1845 book Vail wrote describing Morse’s telegraph, he also attributed the code to Morse.