Metrication matters - Number 8 - 2004-01-10
1 Feedback - notes and comments from readers
3 Oddities - measurements from around the world
4 Tips - pointers and methods to make your measurements easier.
5 Signs of the times
7 Q&A - readers' questions and answers
8 Rule of thumb
10 Hidden metric
I received this observation from a Metrication matters subscriber in the USA. 'I learned the metric system way back in the 8th grade (1968) in my math class from a teacher who was very pro-metric. His basic argument was ease of use. His favorite statement to students who didn't like the metric system was that they should never handle money because it was decimal based'.
In 'Metrication matters 5', I wrote: ' ... because the (US) Government Printing Office insisted that the American spelling of 'metre' is 'meter'. Joe Reid, from Toronto, believes that the USA is the world's only nation that uses this spelling.'
Bill Potts, from WFP Consulting in Roseville California, wrote to say: 'I think you meant to say the world's only 'English-speaking' nation to spell metre as meter. I plead guilty as charged – I misread Joe Reid's remarks. By the way Bill Potts runs the SI Navigator where he directs interested people to all of the world's main metric web sites. I find his free service site – at http://metric1.org/ – very helpful.
Often, when we discuss the use of measuring units, the words right and wrong will appear and they will become the subject of earnest, even vitriolic, debate.
For example, until recently 'The Age', a Melbourne daily newspaper, chose to use the abbreviation 'kph' to mean 'kilometres per hour'. Following informed representation, they have changed their editorial policy so that they now use km/h as the symbol for kilometres per hour – clearly they have now added km/h to their style sheet.
However, if we choose to define 'km/h' as right and 'kph' as wrong, we often find ourselves involved in acrimonious debate. Maybe we should confine our remarks to 'According to accepted international agreement, 'km/h' is regarded as correct, and kph' is regarded as incorrect.
Perhaps using the terms 'correct' and incorrect' will prevent me from getting overly excited about things like: KPHr, KPH, k/h, and kmph (which rhymes with Hhrrrmmmph?).
People sometimes think that the loss of the NASA Mars Orbiter error and the Gimli glider are somehow unusual, but what we hear about aerial accidents due to metric mistakes is really the tip of the iceberg.
In England, a brain surgeon, Mr Donald Campbell, crashed a twin-engine Piper Seneca into a house in Shoreham. Fortunately, although the crash caused major damage to the house, there was no one home at the time, and the brain surgeon received only slight head injuries.
The crash occurred because the plane ran out of fuel because the brain surgeon had asked for 20 gallons (90 litres) instead of the 115 litres he needed for his flight. The BBC reported the same aircraft crash story in detail at:
and the official British government investigation report can be read at:
In heating or cooling a room, increasing or decreasing the temperature by 1°C will save you about 5 % of your energy bill. This 'Rule of thumb' works at the sorts of temperatures we generally use for our comfort, but I can't guarantee its use if you decide to run your thermostat at 0 °C in midwinter – or at 50 °C in midsummer. Remember:
Zero's freezing, Ten is not.
Twenty's pleasing, Thirty's hot.
Forty's frying, Fifty's dying.
5 Signs of the times
Gradually, metrication progress is being made in the USA. Jim Frysinger of Metric Methods reports on his web page that the majority of states in the USA now either 'allow metric–only labelling' or 'are considering metric–only labelling'. Personally, I find the maps that Jim Frysinger uses, at http://www.metricmethods.com/UPLR.html, fascinating.
All around the world evidence is mounting that medical mistakes, many of which involve number and unit errors, are more common than we realise, and that many of these are covered up by legalistic jargon.
A British pharmacy chain wrote a letter of apology to say that an assistant had dispensed the wrong tablet and that the pharmacist had not spotted the mistake. This is part of their letter:
'The cognitive process that staff will go through when interpreting prescriptions and selecting drugs is almost intuitive in that the prescription will be read, a decision is then made in the mind of the individual concerned, they will then make a selection based on what they have decided. When an error is made either mentally or in the physical selection process it is difficult for the individual concerned to detect their own'.
I'm glad that that's cleared up! I wonder why I used the words, 'legalistic jargon'.
Q Can I arrange to have some other members of my department, or for my students, subscribe to 'Metrication matters'?
A That’s easy. Suggest that they point their web browser to: http://www.metricationmatters.com/newsletter.html and they can sign themselves up to 'Metrication matters'.
However, please don't send me names from your address book without asking first if they are willing to receive 'Metrication matters'. I don’t want to be engaged in an anti-spam fight with your aunty or your grandfather whose names came, accidentally, with your list.
8 Rule of thumb
If you want to heat an aquarium allow one watt per litre (1W/L) of water to heat a tropical fish tank. By the way, I am always on the lookout for 'Rules of thumb' to add to my collection. I prefer metric ones but I also convert 'Rules of thumb' from old units to SI units. Please send your 'Rules of thumb' to If you would like me to send you my complete list of 'Rules of thumb', please send your request to:
Han Maenen of the Netherlands suggests that some modern standards may be older than we think. Han says, 'I have now been working in the Nijmegen Public Records Office for about a year and I found out something very interesting: the sequence year-month-day describing dates was already used in the 17th century, among other notations. I found it in baptism, marriage and burial records from a religious denomination in Nijmegen'. He then remarks, 'What is now Standard ISO 8601 dates back for about 300 years!' and 'This notation has also been the standard one in the archives for decades'.
10 Hidden metric
A pro-metric friend from the USA, Carlton McDonald, went for a holiday in Canada. As he put it, 'I wanted three days away from Fred Flintstone Units (FFU) and didn't get it ... ' One of the things he noticed was that 'A bottle of Coca-Cola that was 600 mL a few years ago was now 591 mL. No ounces given, but obviously hidden FFU. Another pro-metric friend, Nat Hager III, pointed out that, '... the 591 mL is probably a Canadian translation of 20 oz, which in turn is a US translation of 600 mL'. So it's double-hidden.
(Oh, what a wicked web we weave, when first we practice to deceive. By the way, I'm still puzzling over whether the ounces are dry ounces or wet ounces or whether they are UK or USA ounces. Ed.)
Pat Naughtin is a writer, speaker, editor, and publisher. Pat has written several books and he has edited and published many others. For example, Pat was the lead writer of a chapter of a chemical engineering encyclopedia, and recently he edited the measurement section for the Australian Government 'Style manual: for writers, editors and printers'. Pat has been recognised by the United States Metric Association as a Lifetime Certified Advanced Metrication Specialist.
Copyright notice: © 2004 Pat Naughtin All rights reserved. You are free to quote material from 'Metrication matters' in whole or in part, provided you include this attribution to 'Metrication matters'. 'This was written by Pat Naughtin of "Metrication matters". Please contact for additional metrication articles and resources on commercial and industrial metrication'. Please notify me where the material will appear. Copying for any other purpose, whether in print, other media, or on websites, requires prior permission. Contact:
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