New York: American Telephone and Telegraph Company 1948. First Edition. vii, 751,  pages. Red buckram library binding with gilt spine lettering and shelf number in white. Ex-library copy with stamps on page edges and endpapers. Properly discarded. In The Bell System Technical Journal, Volume 27, 1948 (entire volume offered). Original wrapper for first issue bound in, the others not present as often the case with library bindings. Soiled upper page edges, speckled edges. Sticker of the Logan Bindery, St. Paul Minn. on front pastedown. Very Good. Cloth. 
The Bell System Technical Journal first published this paper in two parts (July 1948 (pp 379-423) and October 1948 (pp 623-656)). Here offered in a bound volume with other research from Bell Labs in the same year.
"Probably no single work in this century has more profoundly altered man's understanding of communication than [this paper]. Shannon observed that a great many communication systems could be represented [by a simple block diagram]. He constructed simple mathematical models that described the macroscopic functioning of these blocks and studied how these models fit together. This resulted in theorems of great power, elegance, generality, and beauty. They have shed much understanding on the elusive true nature of the communication process and have delineated its inherent limitations." (Slepian, page 1)
"[This paper showed] that all information sources - telegraph keys, people [who are] speaking, television cameras, and so on - have a 'source rate' associated with them which can be measured in bits per second. Communication channels have a “capacity” measured in the same units. The information can be transmitted over the channel if and only if the source rate does not exceed the channel capacity...This work on communication is generally considered to be Shannon's most important scientific contribution... By this landmark paper and his several subsequent papers on information theory, he has altered most profoundly all aspects of communication theory and practice.'" (Sloan/Wyner, p xiii)
By framing information sources in the unambiguous language of mathematics, Shannon enabled engineers and theorists to tackle problems previously inconceivable. A fundamentally important paper.
Sloane and Wyner, "Claude Elwood Shannon Collected Papers," #37
Hook and Norman "Origins of Cyberspace," #880
D. Slepian, editor, "Key Papers in the Development of Information Theory," IEEE Press, NY, 1974, pp 5-29.