Convert Wedgwood to Romer easily.

Trying to convert 18th-century pottery temperatures to Danish astronomer scales? You're not alone. While most people stick with Celsius or Fahrenheit these days, understanding Wedgwood to Romer conversions feels like holding a secret key to scientific history. Let's explore why these units mattered and how to switch between them without losing your cool.

Unit definitions

What is a Wedgwood (°W)?

Josiah Wedgwood's quirky temperature unit was all about clay. Literally. He observed that specific clay types shrink at predictable rates when heated. One Wedgwood unit (°W) equaled 130°C, though some sources argue it was closer to 135°C. The scale became essential for pottery kilns but vanished once modern pyrometers arrived.

Symbol: °W
Common uses: Ceramics, historical temperature records
Definition: Based on clay body shrinkage at high heat

What is a Romer (°Rø)?

Ole Romer's 1701 invention set water's freezing point at 7.5°Rø and boiling at 60°Rø. Fun fact: Daniel Fahrenheit visited Romer and used his scale as partial inspiration. While obsolete now, it's a fascinating midpoint between early mercury thermometers and modern standards.

Symbol: °Rø
Common uses: 18th-century Danish meteorology
Definition: 1°Rø = 40/21 °C

Conversion formula

The math isn't as scary as it looks:
Romer = (Wedgwood × 237.15) + 7.5
Reverse it for Wedgwood:
Wedgwood = (Romer − 7.5) ÷ 237.15

Example calculations

1. Convert 2°W to Romer:
   (2 × 237.15) + 7.5 = 481.8°Rø
2. Convert 100°Rø to Wedgwood:
   (100 − 7.5) ÷ 237.15 ≈ 0.39°W

Conversion tables

Wedgwood to Romer

Romer to Wedgwood

From pottery kilns to star gazers

Josiah Wedgwood (yes, that Wedgwood of porcelain fame) developed his scale around 1782. His method involved heating small clay cylinders and measuring their shrinkage. Each "degree" corresponded to specific physical changes, making it practical for craftsmen without advanced instruments. The scale's benefit was its tactile nature: potters could literally feel when they'd reached the right temperature based on clay behavior.

Ole Romers work in 1701 Copenhagen took a different approach. He fixed two reference points: saltwater freezing (7.5°Rø) and water boiling (60°Rø). This 52.5-degree spread for water's phase change seems odd until you realize Fahrenheit later adapted Romer's ideas, creating his own 32°F to 212°F system. Romer's scale lingered in Scandinavia until the mid-1800s, particularly in meteorological observations.

Interesting facts

1. Wedgwood's clay test pieces were called "pyrometric beads." They changed color at specific temperatures, acting as early temperature indicators.
2. Romer invented the first street lighting system in Copenhagen while developing his temperature scale. Multitasking goals.
3. One Wedgwood degree equals about 237 modern Celsius degrees when converted through the Romer formula.
4. Romer's original thermometer used beer wine instead of mercury. Because why not?
5. Both scales were designed for practical applications: Wedgwood for craft, Romer for civic planning and astronomy.

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