New York: Bell Telephone Laboratories, Inc. 1949. First Separate Edition. 1-40 pages. 21.3 x 27.5 cm (8 3/8 x 10 7/8 inches). Stapled wrappers, printed in grey, light blue, and black. 5 hole punched at the spine, as issued. The first separate edition. Previous owner name "Kay" inked on front cover. Some light scuffing to the covers. Corners creased affecting textblock. Kay was Catherine Kay, Claude Shannon's sister. Very Good. Wraps. 
This is the first separate edition, published in the Bell Telephone System Technical Publications Monograph series, #B-1672. It was first published in the Bell System Technical Journal, Vol 28, pp 59-98, January 1949.
"The Summer of 1940 was spent [ by Shannon ] at Bell Telephone Laboratories doing further research on switching circuits. A new method of design was developed which greatly reduced the number of contacts needed to synthesize complex switching fuinctions from earlier realizations. This was later published in a paper [ as here ]" Sloane/Wyner p xii.
Provenance: From the files of Claude E. Shannon (unmarked).
Literature: Sloane and Wyner, "Claude Elwood Shannon Collected Papers" #50. Not in Hook and Norman, "Origins of Cyberspace"
COLLECTORS NOTE: The Bell System Monograph series is not an offprint series although it is often incorrectly referred to in this manner. It was rather a publication of Bell Telephone Laboratories used to widely distribute (primarily to libraries and large corporations) research articles written by Bell System employees in a variety of widely dispersed publications (including but certainly not limited to the Bell System Technical Journal). The series therefore represents a much broader selection of Bell System research than the Bell System Technical Journal did. Collectors prize this series as they are often (but not always) the first separate appearance of a paper and hence are the closest one can get to the elusive and ever sought after offprint.