Measuring rod
A measuring rod is a tool used to physically measure lengths and survey areas of various sizes. Most measuring rods are round or square sectioned; however, they can also be flat boards. Some have markings at regular intervals. It is likely that the measuring rod was used before the line, chain or steel tapes used in modern measurement. The oldest preserved measuring rod is a copper-alloy bar which was found by the German Assyriologist Eckhard Unger while excavating at Nippur (pictured below). The bar dates from c. 2650 BC. and Unger claimed it was used as a measurement standard. This irregularly formed and irregularly marked graduated rule supposedly defined the Sumerian cubit as about , although this does not agree with other evidence from the statues of Gudea from the same region, five centuries later. Rulers made from ivory were in use by the Indus Valley Civilization in what today is Pakistan, and in some parts of Western India prior to 1500 BCE. Excavations at Lothal dating to 2400 BCE have yielded one such ruler calibrated to about Ian Whitelaw (2007) holds that 'The Mohenjo-Daro ruler is divided into units corresponding to and these are marked out in decimal subdivisions with remarkable accuracy—to within . Ancient bricks found throughout the region have dimensions that correspond to these units.' The sum total of ten graduations from Lothal is approximate to the angula in the Arthashastra. Measuring rods for different purposes and sizes (construction, tailoring and land survey) have been found from China and elsewhere dating to the early 2nd millennium B.C.E. Ancient Egyptian units of measurement Cubit-rods of wood or stone were used in Ancient Egypt. Fourteen of these were described and compared by Lepsius in 1865. Flinders Petrie reported on a rod that shows a length of 520.5 mm, a few millimetres less than the Egyptian cubit. A slate measuring rod was also found, divided into fractions of a Royal Cubit and dating to the time of Akhenaten. Further cubit rods have been found in the tombs of officials.
