§128. The Metric System
The METRIC SYSTEM was developed in France during the decade that followed the French Revolution (1790-1799); the terminology was all drawn from Greek or Latin. The SYSTÈME INTERNATIONAL (SI) is a 20th century refinement and extension of metric, formally approved in 1960; its terminology goes beyond Greek and Latin. An excellent summary can be found in the Encyclopedia Britannica.
| Some original metric measures: | ||
| length | METRE | (< G μετρον): originally defined as “one ten-millionth part of a meridional quadrant of the earth” (the quadrant of the earth’s circumference running from the North Pole through Paris to the equator) |
| area | ARE | (< L area): 10 m x 10 m (= 100 m2) HECTARE (100 ares): 100 m x 100 m (= 10,000 m2) |
| mass | GRAM | (< Late L gramma, “small weight” < G γραμμα): 1 cc of distilled water at maximum density (4°C), weighed in vacuo |
| volume | LITRE | (< ML litra < G λιτρα, “a measure”): a cube 10 cm x 10 cm x 10 cm (1,000 cc); thus l litre of pure water has a mass of 1 kg |
| STERE | (< G στερεος): 1 cubic metre, or a cube 100 cm x 100 cm; thus 1 stere is equivalent to 1 kilolitre. | |
Prefixes in SI Measurement:
| Multiple | Prefix | Symbol | Etymology | |||
| trillion | 1012 | tera- | T | G | τερας | “monster” |
| billion | 109 | giga- | G | G | γιγας | “giant” |
| million | 106 | mega- | M | G | μεγας | “big” |
| thousand | 103 | kilo- | k | G | χιλιοι | |
| hundred | 102 | hecto- | h | G | ἑκατον | |
| ten | 10 | deka- | da | G | δεκα | |
| Submultiple | Prefix | Symbol | Etymology | |||
| tenth | 10-1 | deci- | d | L | decem | |
| hundredth | 10-2 | centi- | c | L | centum | |
| thousandth | 10-3 | milli- | m | L | mille | |
| millionth | 10-6 | micro- | μ | G | μικρος | small |
| billionth | 10-9 | nano- | n | G | νανος | dwarf |
| trillionth | 10-12 | pico- | p | It. | piccolo (?) | small |
| quadrillionth | 10-15 | femto- | f | Dan./Norw. | femten (15) | |
| quintillionth | 10-18 | atto- | a | Dan./Norw. | atten (18) | |
