Does any one know about T.Walker depth sounders? I have one that from
appearance seems to come between the two on exhibit in the NYS Museum in
Albany, NY.

It is two egg shaped brass plates intersected in the center by a brass
propellor of curved flat vanes connected by screw to a brass dial with
numbers. "Walkers Patent Apr 7th 1868" Can one search patents on line yet?
Old ones? And why don't archaeologists search the names of the occupants of
properties for the possibility of patents in the US Patent Office? Wouldn't
this be considered a significant contribution to the national history and
arguable to be nominated to the National Register?

I am particularly interested in barometric instruments ones also, since the
Beagle was sent on a barometric expedition on which Charles Darwin was also
aboard. The origin of these instruments is also important to the South Sea
Seaport history and the history of Italian Americans and Italian Brits since
they marketed them here and there.
Does anyone know of a source for the history and descriptions of the
so-called "banjo barometer"?

George J. Myers, Jr.