Counter Scale.

Unusual English scale with Roberval system. The standard laboratory double-pan balance has a Roberval construction that keeps the pans level as they move up and down. More importantly, it prevents the pans from tilting as they move up and down, and this is the principle that ensures that the position of the weights on the pans has no effect on the balance. Roberval was a French mathematician who invented the system in 1669.

The scale is attached to a cast iron table with two handles and places for five iron weights (4 lb, 2 lb, 1 lb, 1/2 lb, 1/4 lb) and three brass weights (2 oz, 1 oz, 1/2 oz). The base of the scale is nicely decorated and is embossed with "REGISTERED." The load pan is made of iron and is removable; the plate for the weights is iron. England, Ca. 1880.

Tray Scale (No. C642). Dimensions: 13"W x 8"D x 8.5"H, tray is 12"W x 8"D x 2"H. Shipping: $30.