Vintage Pocket Balance Scale ~ Brass Plate ~ Working

This great old pocket scale still works and can weigh up to 25 pounds!  The face plate is brass ~ I think the remainder is iron based on the rustic look of the metal on the hook & ring and under the black paint that has worn away on the back of the scale.

It is marked, "Hughes's - Pocket Balance" and the bottom says "Patent" but there is no patent number that I can see. 

If you have any questions, please let me know.  Thanks.