Prospector's portable assay balance

Prospector's portable assay balance, Oertling model 15, made 1890. Serial no. 3687, capacity 2gms. No vertical pointer but horizontal pointers at each end of the beam pointing to graduated scales fixed to the case. Graduations on right hand side of brass beam for use with a rider, column brass. Signed Oertling, London. Two drawers at base, one containing a box of weights with a machined brass swivel lid (weights serial no. 7238). Flat weights 1gm to 0.01gm.