STATE´RA

STATE´RA a steelyard. This seems to have been an invention of Italy: according to Isidore (Orig. 16.24), it was first used in Campania, and was called and it may be remarked that in Roman remains generally the steelyard is the commonest form of weighing machine discovered. There can be no doubt that the balance [LIBRA] was a far older contrivance than the steelyard: Blümner (in Baumeister's Denkmäler, p. 2078) conjectures as the primitive form a simple bar of wood placed through a ring or loop with the articles to be weighed against each other hung at the two ends. The more elaborate balance was a natural improvement on this, but the steelyard clearly involved more ingenuity and calculation.

An account of the steelyard will be found in Vitruvius, 10.3, 4. The parts defined are the beam or yard (scapus) suspended by a hook or chain which is called the handle (ansa); in this is the point of revolution (centrum), and near it is the from which depends the scale (lancula): on the other side of the centrum the scapus is marked with points (puncta), which express the weight of objects in the scale as the or hanging weight, moves along the beam. This aequipondium was generally adorned with a head divine, human or animal.

 Statera. (From Museum at Rome.)

The example here given is from the Museum of the Capitol at Rome. Others differ in having less ornament; and it is common also to find a hook attached to the shorter arm between the centrum and the which was intended to hold articles whose size and shape made it convenient to hang them on, instead of putting them in the scale, and, as this altered the leverage, there was a double set of puncta on the beam to suit either arrangement. A third kind is shown in Baumeister (Denkm. fig. 2316), where a weight hangs on one arm of an ordinary balance, this arm being marked with It is clear that this was intended for use either as libra or in the former case the weight would be detached; in the latter one scale would be detached (or allowance made for it in the puncta), and the other would be used as in the steelyard.

It must be observed that, though statera is strictly the steelyard, it is often used for a weighing machine of any kind: e. g. in Suet. Vesp. 25, the statera of the dream is clearly a balance with two scales; so also the aurificis statera is doubtless a balance of a peculiarly delicate kind contrasted with the or less carefully adjusted balance; for trutina is used for any weighing machine, without distinction of form. (An illustration of this goldsmith's balance from an ancient relief is shown in Blümner, Technologie, 4.312.)

The engraving in this article shows various weights (aequipondia, σηκώματα), such as may be seen in many museums, and of which a large collection may be studied in the British Museum. There was at Rome a special guild of Sacomarii, or makers of weights (C. I. L. 10.1930; Marquardt, Privatl. 713). For a marble altar set up by a guild of Sacomarii at Ostia, see Lanciani, Ancient Rome, p. 34, London, 1889.

[G.E.M]

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