Landmarks of Human Thought I - Catalog - Page 52
The Key
to identify 昀椀rst editions and later editions of U.S. patents
A
n extensive literature search enabled us to obtain accurate information regarding the
existence of various editions of U.S. patents, especially for important inventions, and to
identify such patents.
Due to the fact that a particular lithographer is marked at the bottom of the drawing sheet(s) in
most cases, and based on information about the lithographers contracted by the USPTO [1] [2]
[6], we were able to create a list which contains the lithographer along with the exact wording
and appearance as printed by the USPTO at the time the patent was granted (昀椀rst edition; see
the Key).
In addition, parts of our U.S. patent collection date from the period covered in the present Key.
In all these patents, without exception, the imprints at the bottom of the drawing sheet(s) match
the lithographer in wording and appearance according to the Key. They are therefore 昀椀rst edition patents and substantiate the Key.
U.S. patents were generally issued weekly on Tuesdays, and contracts with the different lithographers usually changed in the middle of a year. Interestingly, when this change occurred, it
sometimes took the new lithographer several weeks (sometimes months) to mark the drawing
sheet(s). For this reason, there are periods in the Key described as “no lithographer mentioned”.
After November of 1919 the lithographer in charge at the time was no longer imprinted.
From the Of昀椀cial Gazette of the USPTO of January 29, 1907 (Vol. 126, No. 5, pages 1779 and
1780 [2]) we can further deduce that beside the a) current issue later editions, especially
b) reproductions of exhausted copies and c) photographic copies (from mid-1898 onward) were
published if needed (see 昀椀gure 3).
An idea of the average percentage of exhausted copies (later editions) compared to the patents
of the 昀椀rst edition can further be derived from e.g. the Annual Report of the Commissioner of
Patents for the Year 1895 [7]. It states that this percentage was just over one and a half percent
in 1886 and around one and a quarter percent in 1891.
