Abstract
A full detail of metrological system in ancient Mesopotamia has not yet been clarified. The numerical values, having hitherto appeared as the mean values of mass standard, show a variety, one ma-na being indicated as between 489.5-515.75g. Furthermore it is said that there were 1 to 4 different standards. This report aims to offer an calculation of the mean values based on the statisticall method using the firmly dated weights, 74 in number, covering the time-span from ca. 2500 BC to 550 BC. As a result, numerical values as mass of each unit are as follows: 29718g for a gun, 495.3g for a mana, 8.255g for a gin, and 0.04586g for a še. And the following regression equation was obtained by the method of least squares: M=487.6+3.74×10-3t (‘M’ means the mean mass (g) of one ma-na, weights in a certain age and ‘t’ is the number of BC years.) From this equation, it can be concluded that there was little change in the mass standard in ancient Mesopotamia, and becomes clear, from the hallmark on the weights and the histogram of mass of the weights converted into one ma-na, that the mass standard system remained to be single.
