Landmarks of Human Thought I - Catalog - Page 16
Brie昀氀y
demonstrating
the Key
T
homas A. Edison’s “Duplex Telegraph”
U.S. Patent No. 162,633 dated April 27, 1875:
The Key tells us, when looking at the patent date, that the
lithographer is “The Graphic Company”. The exact wording
and appearance must be “THE GRAPHIC CO. PHOTO-LITH.
39 & 41 PARK PLACE, N.Y.“ (see the Key).
This exactly matches Thomas A. Edison’s “Duplex Telegraph”
U.S. Patent No. 162,633 from our collection which is therefore
a 昀椀rst edition print (see 昀椀gure 4).
The imprint from Thomas A. Edison’s “Duplex Telegraph”
U.S. Patent No. 162,633 from the William J. Hammer Collection of the Smithsonian Libraries (1869 – 1884, Volume 1 [8])
reads “N. PETERS, Photo-Lithographer, Washington. D. C.“
(see 昀椀gure 4) and is therefore a later reprint made after the 昀椀re
of 1877, between 1881 and 1890 (see the Key).
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