Fahrenheit

How are you faring in this chill weather? In Toronto, anyone who rides or drives from neighbourhood to livelihood is in for a brisk experience the moment they step into the outside.

How cold is it? It depends on where you are, of course, but in Toronto it is scheduled to pass –18˚ Celsius within 24 hours. For you Americans, that’s below 0˚ Fahrenheit.

I say “for you Americans” because Americans are pretty much alone in the world in adhering to their non-metric measurement scales. While the rest of us deal tidily in decimal, Americans luxuriate in units more suited to measuring quidditch scores and potion portions at Hogwarts. Now, I am on record as saying that cups, ounces, tablespoons and teaspoons are better than metric for kitchen measures because cooking is all about fractions and proportions, and base-10 kind of sucks for those. But for most other things, decimalization would seem to be the way of the future.

I say “would seem” because often it’s not really newer than the Ministry-of-Magic scales you encounter in America. The Celsius and Fahrenheit scales were developed by near-contemporaries (one 15 years younger than the other), and Celsius was standardized to its present values in 1744, while Fahrenheit was standardized to its present values in 1776 (in England – calm down, Yankees).

But the Fahrenheit scale was not developed on the basis of some purely arbitrary values. It originally had its 0 value set as the stable temperature of a mixture of ice, water, and ammonium chloride; its 32 value was set as the freezing point of water, and its 96 value was set as the temperature of a human body as best it could be measured then. Nerds may notice that those are gaps of 32 and 64, which are 2⁵ and 2⁶ respectively – meaning you could mark them, then mark halfway between them, then halfway between the resulting marks, then halfway between those, etc., to mark the values on a thermometer. Easy for the 18^th-century thermometer maker. The only problem is that the original measurements were slightly off. In the end, it was standardized to have water freezing at 32˚ and boiling at 212˚, giving a gap of 180, which is a number that is also quite usable for fractions, being 2×2×3×3×5. (This also means that there are exactly 9 degrees Fahrenheit for every 5 degrees Celsius, making it the tidiest metric-Imperial conversion going. You just have to remember to add or subtract 32 as appropriate.)

But there is another story about how the value of 0˚ really got to be set. It seems that in 1708–09 it was a cold winter in Danzig – also known as Gdańsk; it was part of Germany then but is part of Poland now. How cold? It got down to the temperature we would now call 0 Fahrenheit. That, the story goes, was set as the 0 (because when would you need a number lower than that?), and the chemical mixture excuse was come up with later to justify it more scientifically.

Why Gdańsk? Because that’s where Daniel Gabriel Fahrenheit was born in 1686. He would have been 22 during that winter. He did travel abroad from his hometown, certainly; his father was a merchant, and after Daniel Gabriel’s parents died in 1701 from eating the wrong mushrooms (and not from anything to do with the birth of Anders Celsius that year), the young Fahrenheit travelled to make his way in the world, gaining experience with his miles (or kilometres – or leagues, fathoms, furlongs, whatever). But he would have been back in Gdańsk by that cold winter. After that, he moved to Amsterdam and visited England. In 1724 he published a paper in the Philosophical Transactions of the Royal Society, “Experimenta et Observationes de Congelatione aquae in vacuo factae,” which set out his initial scale.

Which leaves one important question: What’s up with that name? Fahrenheit.

If you know anything about German, you’ll pick it out as a German name, and it is. If you know enough German to speak it, you’ll pick out the bits it’s made of: fahren, a verb cognate with English fare and meaning ‘travel, ride, drive’, and –heit, a suffix cognate with English –hood and used to make abstract nouns. Yes, the family name was made from an abstract noun, just like Celsius. Only I don’t know exactly when and how they made it – his great-grandfather already bore it.

So, though. ‘Faringhood’? What the heck is that? Well, Fahrenheit isn’t used as anything other than a name in German now, but apparently its best translation as a plain noun is ‘experience’.

Young Fahrenheit got lots of experience through travel. And we experience just how the temperature is faring when we fare from one place to another.

And, to be fair, 0˚ doesn’t sound as bad as –17.777778˚. Does it?