Portable chemical balance, made by J. B. Dancer, Manchester, c.1855 and used by James Joule. Has spring-loaded frame and swinging brackets on the box with pins to support the pans. Missing case - there are screw holes at the edge of the base. Lowery (1931) states that the case was removed to facilitate photography of the balance. He described five weights of 1000, 400, 300, 200 and 100 grains.