Add one or both slotted weights to the hangar to weigh letters of  2, 3 or 4 oz !

Letter Scale by unknown maker, c1880. The ball-weight is fixed to the hangar, providing the capacity of 1 oz. Two additional slotted weights are placed on the top of the pillar, 1 & 2 oz. Letters are placed on their edge in the cast brass letter-rack. There are several decorative variations on this theme, including brass-inlaid bases and version where the scale are held by a bronze figure of a lamplighter, or a knight in Armour. These scales were normally given a rich black-brown patina by the maker. Sometimes, the ball-weight is on a chain instead of a hanger.