Hello;
I'm afraid I joined this group to pick your brains. I inherited a
cylindrical slide rule called "Thatcher's Calculating Instrument" from
my grandfather. The machine appears to be in perfect condition (albeit
somewhat yellowed with age), in a well-made wooden box with a book of
directions (1932 copywrite date).

Can anyaone advise me of the potential value of this instrument?

Thanka you in advance for your consideration

Dave Eizinger