Tuesday, May 22, 2007

Searching 19th Century Patents

During a recent visit to the Shelburne Museum in Vermont, I snapped this photo of a handsome iron matchbox on display in the museum's 19th century general store. The cover is embossed with a hunting scene... a dog carrying a duck.

It wasn't clear to me when the matchbox was made, but the text "PATD JAN 21 1862" suggests that the design was patented on January 21, 1862. It was common practice in the 19th century to include the date of issue but not the patent number on patented products, especially articles of manufacture. Fortunately, it is possible to retrieve early U.S. patents from the
USPTO database by date of issue and a search (isd/18620121) retrieves some 50 patents issued on Jan. 21, 1862. Flipping through the first ten or so hits, I was able to quickly locate patent no. 34,230, an "improved box for matches" patented by Henry Howson of Philadelphia and assigned to W. F. Warburton. However, the drawings seemed to me to be very different to the finished article. Might there be a later patent? I zipped over to Google Patents and searched "Henry Howson" and found patent no. 39,994 issued on Sept. 15, 1863. The drawings and description in this patent more closely resemble the matchbox above. Howson also cites his 1862 patent. This is a good example of how to trace 19th century patents and why it's never safe to assume that the date embossed on an article of manufacture corresponds to the final patent. It's always wise to check for later improvements.