The scales were made by Harrison (Birmingham), founded 1898, which went on to become Harrison Drape. Balance scales for full and half sovereigns also measured the circumference and the thickness. As gold is one of the heaviest metals one way to forge a sovereign in brass would be to make it slightly larger to make up the weight. This clever invention put a stop to that.An item from an outstanding and diverse collection of photographs, postcards and artefacts, assembled by members of the Christian and Washfold families of Kew. Harrison Brass Sovereign Rocker Coin Scale in original leather container. The balance scale for full and half sovereigns also measured the circumference and the thickness. It was made from the 1850s to the early 1900s. Scales in perfect condition.cairn scales, sovereign rocker scale, christian-washfold collection