Brass self-indicating Letter Balance with case, 1863, (Hall's patent, made by Parnell, London). Indicating from 0 to 4oz. with corresponding letter charges up to 8d (2d per 1oz.). Sensitivity 30.0gr.
Postal balance, Hall's patent, made by Parnall, London for estimating the postage due on letters being sent by mail. Patented by the inventor in 1863, the self-indicating balance works on the pendulum principle.
Brass self-indicating Letter Balance, 1863, (Hall's patent, made by Parnell, London). Indicating from 0 to 4oz. with corresponding letter charges up to 8d (2d per 1oz.). Sensitivity 30.0gr.
Case for brass self-indicating Letter Balance, 1863, (Hall's patent, made by Parnell, London).
