Antique Apothecary balance scale: arrow points to balanced. From the days when you could buy cocaine, morphine laudanum and other such drugs over the counter from the apothecary. This scale is an early version as evidenced by the arrow balance points.
Marked "Henry Thoemner NO. 12 Philadelphia" on the front of the lid.
The No.12 was manufactured by Troemner for
many years. There is a weight basin in the center of the
marble top. The 1928 catalog description for your scale reads as
follows: Famous No. 12 Box Prescription Scale Class "A". in French
polished ebony box, with white marble top, countersunk weight basin,
glass hinged cover, provided with stop hinges; one of the Finis scales,
and very popular. Solid nickel pans. Screw-leveling feet. Number 12 capacity 1/2 ounce 3 inch
diameter pans. Price in 1928 was $35.75.