There’s little question about whether gas prices are rising. You can check whether the gas station signs are getting taller. But are the prices increasing as well as rising? Those varied collections of digits don’t grow on trees, not anymore. The last grove of wild price-berry trees grew in Maine’s upper peninsula until 1914, when spoilsport geographers pointed out Maine hasn’t got any upper peninsula. An effort to transplant them to the New Hampshire panhandle failed for similar reasons.
The history of gas prices traces back to the Babylonians. One fragmentary parchment a scant three cubits by five reads “DXXXIX OCTANE .XIXIX”. This shows how thousands of years ago, before not only the invention of unleaded but before leaded was a thing, it was cheaper to get 89-octane regular. The meaning was unclear to the Babylonians, because they hadn’t invented Roman Numerals yet. (Roman Numerals were invented by early Renaissance mathematicians to make their early work look more classy.) The Babylonians were pretty hazy on the concept of Rome and whether it would go anywhere too. It’s more sort of sprawled than gone anywhere.
Even once they found out what Roman Numerals were there was still confusion . For example, everyone was pretty sure that “D” is how the Romans wrote “500”. “Fifty” should be something else, like a letter φ. The sad thing is there’s no way to find out. We have to stumble through and tell ourselves if we’re confused it’s probably because we missed something. Maybe it’s a letter ‘T’. That seems like it ought to be a Roman Numeral for something.
Today, gas prices are generally obtained through mining. Most 9’s come from three former mountains in Pennsylvania and West Virginia. Even digits, most often, are taken from Kentucky or the Ozark Mountains when the owners aren’t looking. The odd numbers 1, 3, and most 7’s are dug from former silver veins in Nevada. Other 7’s come from the lower Mississippi region, the onetime “breadbasket of numbers that look random-ish”. The mighty 5 is produced by the one remaining open plant at Washington state’s Hanford Nuclear Plant. This is a highly industrial process. It creates 5’s by fissioning off either a 2 from existing 7’s, or a 3 from an existing 8. A project in the Princeton Plasma Physics Laboratory in early 1994 fused a 2 and a 3. But the operation wasn’t practical, just pretty. There’s still sometimes talk about reviving the project and hoping it works out better. It’s nice to hope for, but don’t count on anything.
As long as gas prices have been for sale people have been trying to find ways around paying them. One one approach is to use prices that are not actually written down but are on electronic signs instead. These are easy to change, so gas station owners can respond to things like the crisis in vanadium. I’m assuming there’s a crisis in vanadium. It seems like the kind of element that’s always having crises. But there are disadvantages. A physically written price needs to be paid for once and then used however long the gas station owner wants. With electronic prices you keep owing typeface royalties to either the Caslon family or the Mergenthaler heirs. Cross them at your peril.
What of the quirk of ending gas prices with a 9/10? The United States has not minted a 9/10-cent coin except briefly in 1831. This was when the Second Bank of the United States was feeling all sarcastic towards President Andrew Johnson. It was a great moment of pettiness, but they looked foolish when they remembered Johnson wasn’t in office and they meant to snipe at Andrew Jackson. The modern uses of 9/10 traces to the Second World War. A War Production Board order of January 1943 restricted the use of the fractions between 91/100 and 99/100. For the duration prices went from ending in 99/100 down to 9/10. Then people got so comfortable with that they didn’t feel like changing back when fraction rationing ended in March 1945.
Many non-United States countries sell gas by the liter, rather than the gallon. Thus they use the same prices but at different times. This inspires curious feelings of nostalgia or a sense of peeking into the future, depending on when one happens to be overseas, and when one should be otherwise.