Cardo
（
θαιρός, στροφεύς, στρόφιγξ, γίγγλυμος). A hinge, a
pivot.
The first figure in the annexed illustration is designed to show the general form of a door,
as we find it with a pivot at the top and bottom (
a b) in ancient remains
of stone, marble, wood, and bronze. The second figure represents a bronze hinge in the
Egyptian collection of the British Museum; its pivot (
b) is exactly
cylindrical. Under these is drawn the threshold of a temple, or other large edifice, with the
plan of the folding-doors. The pivots move in holes fitted to receive them (
b
b), each of which is in an angle behind the antepagmentum. When Hector forces the
gate of the Grecian camp, he does it by breaking both the
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Door and Hinge.
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hinges (
ἀμφοτέρους θαιρούς）—i. e., as
explained by the scholiasts, the pivots (
στρόφιγγας) at the
top and bottom. See
Cataracta.
According to the ancient lexicons,
cardo denoted not only the pivot,
but sometimes the socket (
foramen) in which it turned.
Postis appears to have meant the upright pillar (
a b) in
the frame of the door. The whole of this “post,” including the pivots,
appears to be called
στροφεύς and
cardo
by Theophrastus and Pliny , who say that it was best made of elm, because elm does not warp,
and because the whole door will preserve its proper form, if this part remains unaltered.
The Greeks and Romans also used hinges exactly like those now in common use. Four Roman
hinges of bronze, preserved in the British Museum, are shown in the following illustration.
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Cardines. (British Museum.)
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The proper Greek name for this kind of hinge was
γίγγλυμος:
whence Aristotle applies it to the joint of a bivalve shell; and the anatomists call those
joints of the human body
ginglymoid which allow motion only in one
plane, such as the elbowjoint.
The form of the door above delineated makes it manifest why the principal line laid down in
surveying land was called
cardo (see
Agrimensores); and it further explains the application of the same term
to the North Pole, the supposed pivot on which the heavens revolved (Ovid,
Epist. ex Pont. ii. 10, 45). The lower extremity
of the universe was conceived to turn upon another pivot, corresponding to that at the bottom
of the door; and the conception of these two principal points in geography and astronomy led
to the application of the same term to the east and west also. Hence our “four
points of the compass” are called by ancient writers
quatuor cardines
orbis terrarum; and the four principal winds, N., S. , E., and W., are the
cardinales venti (
Serv. ad
Verg. Aen. i. 85).
