Convert Newton to Reaumur with confidence.
1 °N x (80÷33) = 2.424 °Ré
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Ever wondered how 18th century scientists measured temperature before Celsius and Fahrenheit dominated? Let's explore two fascinating historical scales: Newton and Reaumur. While you won't find these in modern weather apps, understanding their relationship reveals how measurement systems evolve. Whether you're deciphering old recipes or studying scientific history, converting between Newton and Reaumur becomes surprisingly relevant.
Unit definitions
What is a Newton (°N)?
The Newton temperature scale was proposed by Sir Isaac Newton in 1701. Yes, the same Newton who discovered gravity. His thermometer used linseed oil instead of mercury, with 0°N as snow's melting point and 33°N as water boiling. Symbol: °N. Mainly used in early thermodynamics experiments before being replaced by more practical scales.
What is a Reaumur (°Ré)?
Created by French scientist René Antoine Ferchault de Réaumur in 1730, this scale sets water's freezing point at 0°Ré and boiling at 80°Ré. Symbol: °Ré. It became popular in Europe for over a century, particularly in food production and metallurgy, thanks to its decimal-friendly 80-degree range between benchmarks.
Conversion formula
The magic equation connecting these scales:
Réaumur = Newton × (80/33)
Or if you prefer fractions:
°Ré = °N × 2.4242
Why this ratio? Newton divided his scale into 33 equal parts between freezing and boiling, while Réaumur used 80. The conversion factor simply bridges these different divisions.
Example calculations
- Newton to Réaumur:
Let's convert 16.5°N (room temperature in Newton's time):
16.5 × (80/33) = 40°Ré - Réaumur to Newton:
A cheese cave requires 24°Ré:
24 × (33/80) = 9.9°N
Conversion tables
Newton to Reaumur
| Newton (°N) | Reaumur (°Ré) |
|---|---|
| 0 | 0.00 |
| 5 | 12.12 |
| 10 | 24.24 |
| 15 | 36.36 |
| 20 | 48.48 |
| 25 | 60.61 |
| 30 | 72.73 |
| 33 | 80.00 |
Reaumur to Newton
| Reaumur (°Ré) | Newton (°N) |
|---|---|
| 0 | 0.00 |
| 10 | 4.13 |
| 20 | 8.25 |
| 30 | 12.38 |
| 40 | 16.50 |
| 50 | 20.63 |
| 60 | 24.75 |
| 70 | 28.88 |
| 80 | 33.00 |
Historical context you can't ignore
Newton's foray into thermometry began as a side project to his optical studies. His original 1701 paper described using linseed oil because mercury wasn't widely available. The scale's limited adoption wasn't due to inaccuracy, but rather the inconvenience of 33-degree increments. Can you imagine calculating thirds of degrees in pre calculator times?
Réaumur's version arrived three decades later with better marketing. The 80-degree span between water's phase changes made calculations easier in base-10 systems. French winemakers particularly benefit from this scale when monitoring fermentation temperatures. By the 1840 s, both scales began fading as Celsius offered simpler 100-degree intervals aligned with metric standardization.
Interesting facts
- Newton's thermometer required constant stirring to ensure even heat distribution
- Réaumur scale remains in use today for measuring milk acidity in some European dairies
- 0°N corresponds to -2.91°C on the modern Celsius scale
- Russia officially used Réaumur until 1927
- The highest recorded temperature in Newton scale: 132°N (melting lead)
FAQ
Isaac Newton created his scale to explore heat measurement using reproducible reference points like melting snow and boiling water, which later influenced modern thermometry.
Mostly obsolete, but you'll occasionally find it in European cheese production recipes or historical climate records from 18th-century Europe.
Surprisingly precise for its time, but Newton himself noted inconsistencies due to using linseed oil instead of mercury in early prototypes.
Absolutely. Just reverse the formula: Newton = Reaumur × (33/80). Our converter tool handles both directions automatically.
Primarily France, Germany, and Russia until the Celsius scale became dominant in the late 19th century.