Roman Measurements

  • The Roman Weights and Measures were derived from the Ancient Greeks.
  • Roman Weights were mostly based on factors of twelve. Roman linear Measures were based on the Roman foot. All Roman Amphorae were based on a Standard Amphora kept in the Temple of Jupiter in Rome.

1. Roman Distances

  • Unciae (Inches)
    • Inches, the smallest unit.
  • Pes (Foot)
    • The Foot is 12 Unciae or inches or 16 Digiti (Fingers).
  • Passus (Pace)
    • The Pace (Passus) is 5 Pes or feet (meaning pace).
  • Stade
    • The Stade is 625 feet. Stadia were used for sea distances.
  • Roman Mile (mille passus)
    • A 1,000 paces (mille is a thousand, passus is paces).
    • (The Greek Mile was 8 Stadia of 600 feet (not 625 feet). The English mile is 8 Furlongs, a Furlong is 10 chains. (A Furlong was the length of a furrow.)
  • League
    • The League is 3 miles (5km) (The distance a man could walk in one hour)
  • Schoenos
    • From the Greek ‘Schoinos’ meaning Rope, the Schoenos is 40 Stades or 5 miles (8km).
  • Odometer
    • The Roman odometer was a Measuring Wheel.
    •  Vitruvius used an odometer based on the 4 foot (1.2 m) diameter of the Roman chariot wheel which turned 400 times to give one Roman Mile.

2. Roman Cart Gauge

  • The Cart Ruts in Pompeii have been measured at approximately 4 feet 9 inches (1.45 m).
  • This was the width that allowed two horses to be harnessed together and pull a cart.
  • If Medieval Carts didn’t fit the Ruts in Roman Roads, they risked breaking a wheel.
  • So most Medieval Carts were built to the same gauge as Roman Carts, a tradition that carried on up to the nineteenth century CE.

Standard Gauge

  • The Gauge of the 18-19th century Colliery trucks in Northern England was 4 foot 8 inches (1.45 m) because it was based on the cart ruts in the Roman Roads.
  • It was the Gauge introduced by George Stephenson on his early Railways, but he added an extra half an inch to help prevent binding on curves, making the Gauge 4 foot 8 1/2 inches.

3. Roman Weights

  • Uncia (oz)
    • The base unit (one modern ounce, abbrev. oz. (28 grams)
  • As
    • This was 6 Uncia (168 gms).
  • Libra (lb)
    • This was 12 Uncia (336 gms). Libra abbreviates to the English pound (lb) and weighed 3/4 lb.
  • Roman Scales
    • The Roman Scale was an instrument used for weighing which consisted of two types of balance:
      • One was a lever, suspended in the centre, to two arms of equal length, with the scales hanging from each end.
      • The other was also a suspended lever, but with arms of unequal length. The item to be weighed was attached to the smaller arm and the weight was then moved out along the notched arm until it balanced.

4. Roman Volume

  • The Units
  • Ligula
    • smallest unit of volume
  • Quartarius
    • 12 Ligulae
  • Hemina
    • 24 Ligulae
  • Sextarius
    • 2 Heminae
  • Congius
    • 12 Heminae
  • Modius
  • Urna
  • Amphora

Roman Water Engineers

  • Vitruvius (c.88-c.26 BCE)
    • Vitruvius was a Roman Engineer who wrote ‘De Architectura’ (c.15 BCE) where he includes a general section on Aqueducts and describes the Regulations for their construction. Rome had 11 Aqueducts.
  • Archimedes Principle
    • Vitruvius is the source of the story about how Archimedes calculated density using volume.
    • Archimedes stated that the amount of water displaced by an object was equal to its volume. Then if its mass was divided by its volume, it would equal its density.
  • Frontinus (c.35-c.103 CE)
    • He became Prefect of the Aqueducts of Ancient Rome or ‘Curator Aquarum’ in 97 CE.
    • He published a work titled ‘The Aqueducts of Rome’ in which he stated that nine Aqueducts supplied water to 39 Fountains and 591 Public Pools.
    • Frontinus refers to a unit called the Quinaria, a five pipe capacity, to measure flow-rate in the aqueducts.

 

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