Chatillon's spring balance scale.

Spring balance, weighs up to 60 pounds. Vertical, rectangular sheet iron case has hanging ring at top and looped hook at bottom. Brass faceplate is stamped at center with a dial graduated to 20 pounds, every two pounds numbered and ounces marked; product name and information appear above and below. Slide at bottom end is marked for every revolution or 20 pounds up to three revolutions. Cast iron pointer.
Maker is John Chatillon & Sons of New York, NY; 1835-present.

c 1840 - 1870.