431. English Balance Scale. Roberval principle. Equal arm. All-brass, 5-1/4" high. Clover-shaped base 10-9/16" wide x 7-5/8" deep, engraved and filigreed. Four nested weights in center receptacle. Postage rates inscribed on right plate. Signed: "Townshend." Markings: "Warranted Accurate. Regd. 100795."