Furlongs per Fortnight

By The Metric Maven

At the first university I attended, it was assigned as a “joke exercise” to compute speeds in Furlongs/Fortnight. I’m not sure what the lesson was supposed to be in this case. It was clear Furlongs per Fornight was an absurd use of units, but was it because they were not metric?—-or because they are an “inappropriate” use of medieval units. My favorite reference book, Measure for Measure has a single conversion factor entry: Furlong/Fortnight -> miles/hour [Campbell Factor] 0.00 372, and thus far I have not discovered who Campbell might be, or have been. So assuming I’ve converted correctly 1 Furlong/Fortnight is 166.31 micrometers/second or about 10 mm per minute and 600 mm per hour. For those who want to add more absurdity, and for those who are just fine with US Customary, there is the FFF system, which uses the Furlong, Firkin and Fortnight as its base units.

Of course, this is just a contrived use of units that is clearly absurd right? Clearly, one would never encounter an everyday computation this absurd. Well, then you underestimate the absurdity of our “customary units.” I often look to see what search terms are used by visitors to The Metric Maven website, and the current list looked rather prosaic, until I hit the sixth entry. It reads: “How many tablespoons are in a quarter cup?” My mind lurched to a halt taking this in. In one question we find so many adverse aspects of the current non-system of measurement it requires elaboration.

First we address the tablespoon issue. Now I hope the person asking is sure it is a tablespoon and not a teaspoon. As I’ve addressed in the past, the confusion of teaspoons and tablespoons is a perennial problem in US kitchens. It also has the downside that it has the potential to kill people. Assuming the inquisitor wants tablespoons, we might just quickly convert it to metric in milliliters. A tablespoon is 14.8 mL which I will round to 15 mL for our purposes.

We next encounter a fraction to dilute the volume of the cup for reasons which are not particularly apparent. It’s quite possible, that the person involved needs 1/4 cup of water for say a taco mix recipe or something, but has only teaspoons and tablespoons in their post-high school flat, and no US measuring cups. Well, we want a quarter cup of liquid, but only have a tablespoon. So a cup converted to metric is 236.6 mL, and we will divide this by four to obtain 59.1 mL which we will round to 60 mL. I might hear some objecting to this, but if the recipe was born of precision, it would have been in metric in the first place.

So now we have a teaspoon is 15 mL and 1/4 cup is 60 mL, we use these integer values to see that wow!–it’s 4 tablespoons in a 1/4 cup! What an interesting coincidence, but also, yeah, a complete coincidence. There is no way that these medieval units would have allowed one to readily realize this fact using them exclusively.

Now let’s look at the same problem from a metric perspective. We need 60 mL of water, milk, olive oil, whatever. Well, we can find a 15 mL measuring spoon and use four of them, or we can find a measuring cup and fill to the 50 mL graduation, then estimate another 10 mL. In the case of water, you could use a scale to measure 60 grams of water which is 60 mL using any vessel after zeroing the scale. It seems like one has a lot of options with a rational measurement system. But why bother when you can just use a search engine to find out the answer? The same type of solution was offered in the early 20th century by Fredrick Halsey, author of The Metric Fallacy. The technical device he offered up that would make the metric system unnecessary was the slide rule.

Technical innovations will not eliminate poor and non-intuitive methods of measurement expression. For instance, another question in the list of search key phrases is “how to use 1/8 inch measurement on yardstick.” Well, I have written about the absurdities of yardsticks in my essay Stickin’ it to Yardsticks. US residents might find it absurd that a person doesn’t recall common denominators, and such. What is absurd is making US residents use fractions on measuring rules at all. If they had a millimeter-only meter-stick there would be no need for fractions, or decimals. The person involved would not need to look on the internet, only understand integer addition and subtraction, and there are plenty of calculators available for that.

Thank heavens we still don’t use Roman numerals when the rest of the world uses Hindu-Arabic ones with decimals, we might rationalize using them in the age of the internet.


Tim Hunkin, a designer and maker from the UK has released his first video about The Secret Life of Components. He discusses chains, and as you will see, uses nothing but millimetres, including a mm-only ruler. He threw out all his quarter-inch US chains as he found the use of “imperial” too confusing. Note that he uses the word mil for millimetre, as is common with British engineers. In the US, the mil is a feral unit. Of course, we also use a pre-metric measurement unit called the chain to build roads in the US. I’ve written about it here.

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Stream of Metric Consciousness

By The Metric Maven

A coffee klatch denizen, NY Joe, kindly brought me a book titled The Macmillan Dictionary of Measurement. It has over 4250 entries and Joe was sure I’d find it interesting reading. He was right, there are many interesting aspects of the book that caught my attention, and some not in a good way. One entry took me by surprise and would have been a nice addition to my DBTC chapter Multiple Metric Systems and Metrology. There I point out the existence of the MKS (meter-kilogram-second), CGS (centimeter-gram-second) and MTS (meter-tonne-second) systems. I encountered an entry about the crinal in this dictionary, which I reproduce below:

Yes, the DKS decimeter-kilogram-second system!? I’ve encountered this system no where else in my research over the years. One might almost think it a joke, but then I’ve seen the seemingly unending historical pre-metric units, and many of them also appear to be jokes. My favorite reference has a crinal in it, and the first definition is 1 decinewton. Indeed, let’s just rid ourselves of the prefix cluster around unity. This is unit proliferation, pure and simple.

I also learned that base ten logarithms, like that used to define the decibel, are called Briggs logarithms after the early British mathematician Henry Briggs (1561-1631). In 1616 he drew up the first base ten logarithm tables. Who knew? For those who find British Thermal Units too straightforward, there is also the CHU or centigrade heat unit, equal to the quantity of heat required to raise the temperature of 1 pound of water by 1 degree celsius. That is a serious pigfish definition. It is also known as the pound-calorie. The international angstrom is a unit of length, but it is defined with a red line in the cadmium spectrum, at a temperature of 15 C and a pressure of 760 mm of mercury which is 6438.4696 international angstroms. “It is very nearly the same as an ANGSTROM UNIT (10-10 m).” What? very nearly the same? Why not call it “the horseshoe?” We also encounter a prefixed angstrom called a milliangstrom. We need a unit that is 10-13 m in length? There is also the kip, which is a: “Little-used unit of mass for measuring the load on a structure equal to 1,000 pounds avdp. (half a short ton). It was named after the first letters of kilo imperial pound.” This is serious pigfish on parade. Shoe sizes are defined, but mondopoint does not have an entry, or a single mention in the dictionary. I have written about mondopoint here and here.

The dictionary even relates a unit called the eric:

Eric [comparative values] In medieval Ireland, the blood money paid by a murderer or accidental killer (to his family) to the victim’s family in full and complete satisfaction for the death, so that no further punishment or obligation would be imposed or sought.

There is also “the finger.” As we know a hand is about 100 mm in width. Four fingers of width implies a finger would be about 20 mm (25 if the world made sense). Of course in old timey movies we see western characters order two or three fingers of alcohol, which is not exactly independent of the size of the glass.

This dictionary has very little use for milli. Millimeters and milliliters appear depreciated for centimeters and centiliters. When millimeters do appear it is often with mixed fractions.

The dictionary has the Kilotonne, which is a metric prefix applied to a Megagram which is actually a Gigagram as I point out in my essay A Kilotonne is how much in metric? The dictionary lists (with lower case of course) a megabar, megabit, megacurie, megadyne, megahertz, megajoule, megaparsec, megarad, megaton, megavar, megavolt, megawatt, and megaohm, but no Megagram! Clearly the authors of this reference, need to become a bit more acquainted with the metric system in my view. They proudly have listed tonne and kilotonne, but no megatonne, or gigatonne. Both of these nested concatenated prefix “units,” which are megamegagrams or gigamegagrams are seen constantly in reporting about global warming and elsewhere, rather than using Teragrams or Petagrams, which are properly expressed, and devoid of the archaic pre-metric “ton”, which only serves as a thumb to suck, or a skirt to hold are absent. Of course the dictionary also has metric ton and tonne

One day while using public transit to meet with me over brunch, Sven noted a fellow wearing a tee shirt like the one below:

Over the years, there has been a meme of sorts that indicates that spelling is somehow a measure of something that is intellectually indicative about a person. As I’ve pointed out, we have a number of Shakespeare’s signatures, and no two are spelled the same. The two people who wrote this book identify themselves on the dust jacket: “[one]….is a packager who produces popular dictionary and reference books in the fields of science, semantics and medicine” and “[the other]…is an editorial consultant who specializes in religion, foreign languages, place-names, and music.” They both spend an inordinate amount of time defining collective nouns, such as a murder of crows, murmuration of starlings, or a muster of peafowl. These are not exactly precisely defined units or values. The reference is indeed written like what one would expect from specialists in language, who I’m sure can spell, but have no metrology background.

Often people ask me to talk about old archaic pre-metric units, but I have no interest in doing so. There are so many “metric” and “pigfish” sub-optimal units to discuss, and then plead for people stop using; I want to concentrate on them. I encourage people to switch-over to pure efficient metric, without the tonne, micron, angstrom, or other “exceptions.” If you want to know about archaic or obsolete units that no one has ever heard of, consult John Quincy Adams. Relating numbers in the most meaningful manner possible begins with good streamlined metric usage.

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