Page:Preliminary Historical Report on the Solution of the "B" Machine.pdf/4

 represents the diphthong ; X represents ; P represents ; V represents ; Q T Q represents ; B K W represents (= United States); T K W represents (= Japanese Government); S N W represents, etc., etc. The difficulties introduced by this abbreviated or rather code writing alone were quite staggering as well as aggravating, for often the "text" even when finally reconstructed appeared more like code or a random assortment of letters than plain text.2 For the reconstruction of such text, the services of the Japanese experts were absolutely essential, and the work went very slowly not only because of its difficulty, but also because the services of these translators were available only a small part of the time when the traffic for the daily "Bulletin" permitted, which was quite seldom. However, occasionally it was found, after the "6's" in a given message had been deciphered, that these letters and their distribution throughout the message gave good indications of the presence, in whole or in part in the message, of normal English text. In such cases, the "guessing" process was likely to be considerably easier because of the absence of abbreviations (except for punctuation signs, in which case these were a help), because of the

2A typical example of the sort of "text" usually found at the beginning of messages is the following:

The correct grouping of letters and the interpretation of the foregoing "plain text" is as follows:

In running language, the message begins as follows: "Number 15 (part 1 of 2 parts) Secret, to be kept within the Department paragraph On March 16th the American Ambassador, Grew", etc.