Technikatörténeti szemle 10. (1978)

A MÉRÉS ÉS A MÉRTÉKEK AZ EMBER MŰVELŐDÉSÉBEN című konferencián Budapesten, 1976. április 27–30-án elhangzott előadások II. - Powell, M. A.: A mezopotámiai súlymértéktan modern szemszögből

and slowly developing more precise units of measurement. The hypothesis offered here seems to me to best explain both the structure of the system and the fact that most Babylonian standard weights incorporate norms implying the existence of a talent or „load" ranging from 28 to 32 kilograms. Thus, as I understand the problem, local factors had a profound effect on the total picture of Mesopotamian weight metrology that we are able to deduce from the surviving weight-specimens. There were, however, other factors influencing the development of Mesopotamian weight metrology. Thes factors were, above all, the standards used by the central government and those used by the various temples. It is clear from the ancient documents and from surviving weight-specimens that both the central government and the large temple households had their own standards of measurement. The kings established standards of measurement as an index for interpreting legislation regarding prices, and the temples used their own standards in issuing and receiving commodities, and there can be no doubt that the prestige, and probably the reputation for fair-dealing on the part of the temple and palace, acted as a stabilizing factor in Mesopotamian metrology. Nevertheless, there is no evidence for an attempt to establish and enforce uniform standards of measure. In addition to the royal and temple standars, there were also many local and private standards, such as those used by merchants and tavern keepers. All of these standards, however, fluctuated around the mina norm of 504 grams. Deviation from this standard varies considerably, depending upon three factors: the time period, the quality of the material from which the weight-standard was made, and the size of the specimen. As a'rule of thumb, it can be stated that the weight norms from the third millenium tend to be somewhat heavier than those from the second millennium. It must be noted, however, that the exact pattern of changing norms with respect to time and place cannot yet be determined exactly. Both more study and more evidence are necessary before this can be done. The range of deviation from the norm within groups of weight-specimens that come from one place and from the same time period depends above all on the quality of the weight-specimen and the mass of the units involved. With regard to the quality of the weight-specimens, the following principles can be laid down. In Babylonia, from about 2000 BC onward, precision weights having a mass of one-third mina or less (168 grams) were always made of hematite. In a group of 59 perfectly preserved specimens from Neribtum, an ancient town lying east of the Tigris and south of Baghdad, standard deviation from the mina norm of 504 grams was 16 grams. In groups of non-precision weights, the standard deviation rises as high as 34 grams at the mina. The second factor influencing deviation from the norm is the size of the unit of mass. This has a profound effect on standard deviation, for one finds that deviation from the norm increases as the size of the unit decreases. Actually, this is only a rough approximation of the real situation, from standard deviation remains fairly constant until the unit of mass becomes smaller than one shekel (8.4 grams). Even the units two-thirds and one-half shekel (5.6 and 4.2 grams) are relatively stable, but below 4.2 grams, the mass of units begins to fluctuate significantly, and it is here that the greatest deviation from the norm occurs. This might appear to be extremely unfortunate for a study of metrology, and, indeed, it would be if we defined metrology narrowly as the determination of pre-