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
trutina
campana; 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
caput, 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
aequipondium, or hanging weight, moves
along the beam. This aequipondium was generally adorned with a head divine,
human or animal.
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Statera. (From Museum at Rome.)
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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
caput, 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
puncta. It is clear that this
was intended for use either as
libra or
statera: 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
popularis
trutina, 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]
