By The Metric Maven
My favorite meat market is supervised by a long-time Irish immigrant to the US. He is of good humor and was pleasantly surprised when he realized why I came in and generally ordered 0.45 pounds of hamburger. “It’s 200 grams” I pointed out one day. Like most persons who have lived in countries with the metric system he immediately exclaimed “The weights and measures here are crazy, I don’t understand why they do it. It took me a long time to get used to them.”
He noted that people can be very exacting about their measures. One day a patron asked for a steak cut to one-quarter of an inch. When it was placed on the scale, the Irishman asked if that was good. The customer reached into his pocket, produced a tape measure, measured the steak’s thickness and indicated it was close enough. The Irishman was floored by this.
During the Winter, I generally carry a millimeter-only tape measure with me. I produced it and told him that from now on I was going to demand my steaks be to the millimeter. The Irishman assumed it was an inch measure, so I pointed out that it wasn’t. He was so surprised he came around to the customer side of the meat counter to get a better look at it. We commiserated about the lack of the metric system in the US. Now and then when I would come in I would pull out the tape measure and say “I need steak—to the millimeter.”
The market has been around since the 1940s and is still a “small-town” feeling independently owned family business. The people behind the counter recognize me when I do business there. One day I was asked “You’re the metric guy—right?” I admitted I am. He asked: “If we switched over to metric, how would we do business? how would we measure things?” I told him that only grams would be used mostly, and pointed to my blog showing how the UK packages its foodstuffs. “You would think of 1000 grams as a Kilogram or 2500 grams as 2.5 Kilograms with very little thought.” The values you would use would generally be all integers without a need for decimal points. He seemed interested. Liquids would all be measured in milliliters and would also be integer values without decimal points. You would sell 300 mL of barbecue sauce, or 250 mL of mustard, it would all be simple numbers. The person behind the counter was still not convinced. I jokingly said I would report his intransigence to the Irishman.
As I was driving back to my residence with my 200 grams of ground beef, I wondered what the best value for pre-packaging might be. When one goes into an ordinary chain grocery store in the US (not my meat market) the beef is generally found in one-pound packages. They are not really 1 LB, they are 1.15, 1.2, 1.1 and so on. Now and then you will find some that are 1.00, but it’s not a requirement obviously. It struck me that the constant argument for Ye Olde English measures is how convenient they are, despite their obvious awkwardness as in the case of pounds and ounces. If you buy one pound of hamburger you can make it two 0.5 LB patties, or three 0.333 pound patties or four 0.25 LB patties. One of the weird arguments made about the meter is that you have to have 0.333 meters when it is divided in three and so without a metric foot the metric system is somehow incomplete and irrational. If the embracers of medieval measures believe this is a valid argument for length, they should also consider it a problem for weight (mass) in Ye Olde English.
It struck me that pre-packaged ground beef could be sold in 600 gram packages. This would make it easy to have two 300 gram patties, or three 200 gram patties, or four 150 gram patties, or five 120 gram patties, or six 100 gram patties. Seven doesn’t work, but you see the point. This is similar to the choice of 600 mm center to center separation in millimeter only metric construction. It makes the simple arithmetic easy and generally works out to whole numbers. Of course this would also be true for 600 mL volumes, should one be interested in dividing them up in the most utilitarian way possible. When I had custom mm only metric rules fabricated to give to my best clients I chose 600 mm. It seemed long enough to measure a large number of everyday engineering objects, and also was a number which is easily divisible with a large number of integers.
If you liked this essay and wish to support the work of The Metric Maven, please visit his Patreon Page
The Metric Maven has published a new book titled The Dimensions of The Cosmos. It examines the basic quantities of the world from yocto to Yotta with a mixture of scientific anecdotes and may be purchased here.