Candlepower Was a Real Unit of Measurement
A candle burns wax around a wick. For a century the brightness of a standard candle defined how light was measured.
A candle is a wick embedded in wax that burns to give light. It was also a scientific instrument: *candlepower* was defined in Britain by the light of a spermaceti candle of specified weight burning at a specified rate. The modern unit, the candela, replaced it in 1948 but kept the name and roughly the same value.
- A wax light source. *Light a candle.*
- Candlepower — a former unit of light. *Fifty candlepower.*
- Not hold a candle to — be far inferior. *He cannot hold a candle to her.*
Word forms
| Form | Word | Example |
|---|---|---|
| Noun | candle | A tall candle. |
| Plural | candles | Birthday candles. |
| Compound | candlestick | A brass candlestick. |
| Unit | candela | One candela. |
| Related | chandelier | A crystal chandelier. |
How it is used in a sentence
- He burns the candle at both ends.Exhausting himself.
- The game is not worth the candle.Not worth the cost, from card play by candlelight.
- The candela replaced candlepower in 1948.Metrology.
Candle idioms
- Burn the candle at both ends — exhaust yourself
- Not hold a candle to — from the apprentice who held light for a master
- The game is not worth the candle — the cost outweighs the gain
- Candle in the wind — something fragile
- Roman candle — a firework, and a skiing tumble
From Old English *candel*, from Latin *candela*, from *candere*, to shine — the same root as *candid*, *incandescent* and *candidate*.
Are candle and candidate related?
Yes. Roman candidates wore bright white togas, from *candidus*, shining white, from the same verb.
What is a candela?
The modern unit of luminous intensity, defined precisely in physical terms but set to roughly match the old candlepower.