††Scales are an instrument for weighing. They use the principle of gravity. They compare the weight of an object in one pan to a known weight which is placed in the other pan. Weighing scales are probably one of the oldest measuring instruments. They were probably invented by the ancient Babylonians or Egyptians about 5000 BC. Then they were used for weighing gold dust for jewellery and commercial goods being exchanged for barter, rather than payment for a weighed amount. These early scales consisted of a simple beam pivoted at its centre, with standard weights in a pan at one end and the object to be weighed in another pan at the other end. The Romans made an important improvement to the design of scales when, at the point at which the beam is pivoted, they fixed a triangular 'knife edge' fulcrum to the beam. This made the balance more sensitive and accurate, especially when measuring very small weights.
