Quinaria
Encyclopedia
A quinaria is a Roman
unit
of area
, roughly equal to 4.2 square centimeters (0.65 sq in). Its primary use was to measure the cross-sectional area of pipes in Roman water distribution systems. A "one quinaria" pipe is 2.31 centimeters (0.91 in) in diameter.
In Roman times, there was considerable ambiguity regarding the origin of the name, and the actual value of a quinaria. According to Frontinus
:
In other words, Vitruvius
claimed that the name was derived from a pipe created from a flat sheet of lead "5 digits
wide", roughly 9.25 centimeters (3.64 in), but Frontinus contested the definitiveness of this because the exterior circumference of the resulting pipe would be larger than the interior circumference. According to Frontinus, the name and value is derived from a pipe having a diameter of "5/4 of a digit". Using Vitruvius' standard, the value of a quinaria is 6.81 square centimeters (1.03 sq in), and the resulting pipe would have a diameter of 2.94 centimeters (1.16 in).
Ancient Rome
Ancient Rome was a thriving civilization that grew on the Italian Peninsula as early as the 8th century BC. Located along the Mediterranean Sea and centered on the city of Rome, it expanded to one of the largest empires in the ancient world....
unit
Units of measurement
A unit of measurement is a definite magnitude of a physical quantity, defined and adopted by convention and/or by law, that is used as a standard for measurement of the same physical quantity. Any other value of the physical quantity can be expressed as a simple multiple of the unit of...
of area
Area
Area is a quantity that expresses the extent of a two-dimensional surface or shape in the plane. Area can be understood as the amount of material with a given thickness that would be necessary to fashion a model of the shape, or the amount of paint necessary to cover the surface with a single coat...
, roughly equal to 4.2 square centimeters (0.65 sq in). Its primary use was to measure the cross-sectional area of pipes in Roman water distribution systems. A "one quinaria" pipe is 2.31 centimeters (0.91 in) in diameter.
In Roman times, there was considerable ambiguity regarding the origin of the name, and the actual value of a quinaria. According to Frontinus
Sextus Julius Frontinus
Sextus Julius Frontinus was one of the most distinguished Roman aristocrats of the late 1st century AD, but is best known to the post-Classical world as an author of technical treatises, especially one dealing with the aqueducts of Rome....
:
...Those who refer (the quinaria) to Vitruvius and the plumbers, declare that it was so named from the fact that a flat sheet of lead 5 digits wide, made up into a round pipe, forms this ajutage. But this is indefinite, because the plate, when made up into a round shape, will be extended on the exterior surface and contracted on the interior surface. The most probable explanation is that the quinaria received its name from having a diameter of 5/4 of a digit...
In other words, Vitruvius
Vitruvius
Marcus Vitruvius Pollio was a Roman writer, architect and engineer, active in the 1st century BC. He is best known as the author of the multi-volume work De Architectura ....
claimed that the name was derived from a pipe created from a flat sheet of lead "5 digits
Digit (unit)
The digit or finger is an ancient and obsolete non-SI unit of measurement of length. It was originally based on the breadth of a human finger...
wide", roughly 9.25 centimeters (3.64 in), but Frontinus contested the definitiveness of this because the exterior circumference of the resulting pipe would be larger than the interior circumference. According to Frontinus, the name and value is derived from a pipe having a diameter of "5/4 of a digit". Using Vitruvius' standard, the value of a quinaria is 6.81 square centimeters (1.03 sq in), and the resulting pipe would have a diameter of 2.94 centimeters (1.16 in).