It is probably a cotton scale.

I was told that it was common to have two sets of counterweights. One for
buying and one for selling.

It looks like you got the buying weight.

Paul K. Dickman

"Joe" wrote in message
...
I just bought what I've always called a "hay scale". It's just a
balance beam with a top hook for hanging from wherever, and a bottom
hook for the load. The beam is brass, with a sliding counterweight,
and there are 2 extra weights (iron) for increasing the capacity.
(metal content)

When the counterweight is set to 0, the scale still acts as though
there needs to be more weight attached to the "load" hook. I guess
there was some sort of device added, but I dont know what (if it truly
was a hay scale, I doubt that there would be a pan). The needed extra
weight seems to be on the order of 5 - 10 lbs.

Anyway, I tried searching for information about these things, but got
mostly pay-scale nonsense. Anybody have any links for scale
collectors, or whatever. I have accumulated quite a collection of
various scales and balances, from a lab "chain weight" analytical
balance (measures as little as 0.01 mg), to a Fairbanks-Morse platform
balance that can handle up to 1000 lbs. This is my first foray into
the free-hanging scales, though.

Thanks,
Joe