THE story of MI-2, which served as the intelligence office for the War, Navy, Justice, and State Departments during the war, and as the American Cryptographic Bureau hidden in New York after the war, written with an axe to grind. For the operations of the "American Black Chamber" were brought to a close in March, 1929 by Secretary Stimson, "the first diplomatist who, though well aware that all great powers have their Black Chambers, had the courage, or was it naivete?--to announce that diplomatic correspondence must be inviolate." The dedication page mentions "our skilful antagonists, the foreign cryptographers, who still remain behind the curtain of secret diplomacy."

The author quotes numerous secret diplomatic dispatches from Tokio to Washington during the Washington Conference, which were decoded and translated, showing that a policy of delay on the part of the British and Americans was sure to force the Japanese to retreat, as they did, from their demand for a ten-to-seven ratio. From this one would conclude, that, with the Black Chamber closed, the United States went into the London Naval Conference and will go into any future conference at a disadvantage, unless foreign powers follow Secretary Stimpson's example, "Stud poker is not a very difficult game after you see your opponent's hole card," the author remarks.

But for the most part, when the grindstone is still, the book is an entertaining tale of espionage and of resourcefulness in the conduct of a little advertised but important part of the war machine. MI-8, organized through Yardley's initiative, had its hands full in keeping pace with German chemists, who gave their spies silk scarves, or even silk-covered tuxedo-buttons, impregnated with secret ink chemicals which could be devolped with only one specific reagent. It was the Secret Ink Bureau which brought about the capture of Madame de Victoria, most dangerous of the German spies, who introduced high explosives in marble figures for altar decoration, and was in charge of blowing up war industry plants, docks, etc. in the United States.

Evidently a first-rate cryptographer, Yardley gives a fascinating account of the deciphering of messages between Germany and Mexico, and of dispatches which brought a death sentence to Pablo Waberski. Anyone who has slipped notes between schoolroom desks or fancied "The Gold Bug" will enjoy clear expositions of the decipherment of codes which,--enciphered, transposed, and with "nulls" sprinkled through them--seem quite unassailable to the layman. And the reader will sympathize with Yardley in his struggles with the Japanese code, broken one morning several hours after midnight, after months of struggle with the language, and examination of 10,000 indexed cards compiled from hundreds of Japanese messages.

Incidentally, the book bears out what is common knowledge, that the allies were highly suspicious of each other during the war; the French and British Black Chambers refused to share information which might prove of use to either during the peace negotiations.

The author is conceited, and a few sensational features, such as an insinuation that President Wilson was administered a slow poison by Entente plotters while in Paris, cannot be approved. But the book will afford several entertaining hours, and the reader will perhaps regret that, "with the introduction of mechanical coding machines, cryptography as a science will become a thing of the past.