One potential source of information is Google patents:
http://www.google.com/patents
I pulled up several hits just by typing "steamboat steering" (not in quotes).
Google patents is handy for searching, but the database has many OCR errors and the scans are poor quality. Once you find a pertinent patent, I'd recommend going to the government site for better images to print:
http://www.uspto.gov/
(click on "patents" and search by patent number -- you may need to download a [free] tiff viewer to see and print your results)
Good luck!
Marty Perdue
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----- Original Message -----
From: wayne Abrahamson
To: [log in to unmask]
Sent: Mon, 2 Feb 2009 16:00:31 +0000 (UTC)
Subject: Steering systems on eastern coastal paddlewheel steamboats
I am currently writing my thesis on an eastern coastal paddlewheel steamboat sunk in an Alabama river. I have been very fortunate in gathering a good amount of material concerning the construction and engineering of this type of vessel; however, I could use some input on the unique steering system that was installed on these steamboats. Any ideas or references would be appreciated.