[image of digits]

Collections in Cryptology - Rowlett Papers
Key figures in computation...

Several hundred cryptanalytic worksheets dated 1930-31.


Frank Byron Rowlett
2 May 1908 - 29 June 1998

Married to Edith Jean King 13 September 1928.
Hired by William F. Friedman in 1930 after Friedman was appointed Director of the Army Signal Intelligence Service on May 10, 1929. Also hired were his mathematician friends Solomon Kullback and Abraham Sinkov.

Watermark on many worksheets.

Watermark on many worksheets.
Lt. Laurance F. Safford
Director of Navy Radio Intelligence. Rubber-stamped signature.
There are
only three dated
Rowlett papers.

Names, words and doodles, including Edith Rowett, Zanatti, Frank, John, is, this, count and attic. Calligraphy practice? Daydreaming?

Sketch of the watermark. Who?
Man with sombrero, appropriately on a Spanish language cryptanalytic

An imaginary landscape or a view from the office?

Two of dozens of completed "Cryptographic Sheets," mostly in English but at least one each in German, French and Spanish.