Weight Calibrator

"My uncle-in-law was a weights and measures inspector for the London Borough of Hounslow. In an era when shopkeepers commonly weighed out dry goods -- tea, flour and so on -- for each customer, he used this device to calibrate their weights and verify that customers were getting true weight. He travelled from shop to shop carrying the device folded in its compact carrying case along with a set of standard weights to test the merchants' own weights. The horizontal bar of the calibrator is stamped 'Middlesex County Council' so it predates the London local government reorganisation of 1965."