Metrication matters - Number 4 - 2003-09-10
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
James Jason Wentworth, from Alaska, sent this comment: 'Thank you! I appreciate your providing the "Metrication Matters" newsletter. It contains valuable information for the rank-and-file pro-metricationist'.
Joe Reid, from Toronto, wrote to advise me that the Gimli glider ran out of fuel over western Ontario, not Manitoba. If you missed this story all the details are at http://www.wadenelson.com/gimli.html - and I still find the story fascinating.
A physics teacher told me that he will ask all of his students to subscribe to 'Metrication matters' this year.
And I received a fan letter from my wife, Wendy, who reminded me of the time that I first saw a first edition (1585) of Simon Stevin's 'Disme – The Art of Tenths ' at Trinity College library in Dublin.
It came in its very own, very old box and as I reverently removed the book, its cover came off! And I had to inform the library supervisor.
Wendy included the supervisor's response when she sent a thank-you poem to the book binder of my photocopy that I brought back to Australia.
Thank you for the binding 'Of
Disme, The Art of Tenths'.
The first suggestion of decimals
And it certainly makes good sense.
I got to see a first edition
Some time ago in Dublin.
To my 'Disme' the cover came off
Tho' the library wasn't troublin'.
'To be sure' they said 'and don't be worried,
It often happens round here.
We can't be sure of its condition
It hasn't been asked for in two hundred year.'
But this time round I won't have to panic
My book is solid and sound.
So I 'pointedly' mark you ten out of ten
For a copy so beautifully bound.
The metric prefixes allow us to use numbers that are easy and quick to read whenever we want fast and safe communication, such as on road signs. If a sign is half a kilometre away from a turn, you could write: 1/2 km, 0.5 km, or 500 m. Although these all mean the same thing, it is the last that is preferred by most countries around the world. The first uses a vulgar fraction so it is not decimal. The second uses a decimal fraction with a decimal point that might be missed in less than optimal conditions such as fog, rain, or snow. This also fits well with the odometer in your car, as this is also decimal; cars don't have 1/2s and 1/4s on their odometers.
A bottle became a default standard around the world in the early 20th century. The original bottle size was one twelfth of two Imperial gallons, or 26 2/3rds Imperial ounces. Although this bottle was a sixth of an Imperial gallon, it became known as a 'fifth' in the USA because it was quite close to a fifth of a (USA) gallon.
Prefix mnemonics Many activities have memory helpers for beginners so that they can readily become involved, and they can develop confidence quickly. Well-known examples are the word F-A-C-E used to remember the 'space' notes of the treble clef stave in music. This is associated with the sentence 'Every Good Boy Deserves Fruit' to remember the 'line' notes E, G, B, D, and F.
These memory helpers are technically known as mnemonics, from Greek words associated with mindfulness and remembering. However, I have not found equivalent mnemonics to help young people learn SI basics, such as the names of the prefixes.
I have devised two mnemonics to help people learn SI prefixes easily. Details of the development and rationale for these mnemonics is indicated in these tables.
Prefixes less than 1 (sub-multiples):
Prefixes less than 1 (sub-multiples):
millie, mike's nana, pickled fish at zepto's yacht(o)
Note: I considered fems instead of fish, but I couldn't bear its sound – or its political incorrectness.
Prefixes more than 1 (multiples)
killer Meg, Giggling, Terrified Peter's Extra Zits. Yuk!
Note: I considered 'kindly Meg' but then I grew to like 'killer Meg' much better.
I make no apology for the silliness of the words that I chose for these mnemonics. Mnemonics seem to work best if they contain off-the-wall ideas or reasonably strong rhymes or rhythms; I've been wondering for years why: 'Every Good Boy Deserves Fruit'; but the mnemonic still works, and works well.
5 Signs of the times
Paint makers, in Australia, have devised an odd way to label their paint cans since metrication began in 1970. Paint is usually supplied in 1 litre, 2 litre, and 4 litre sizes, and this binary method of division has been the pattern for household paints in Australia for multiple litre sizes. For sub-litre sizes, paint makers also use the binary system of 500 millilitres (half litre), 250 millilitres (quarter litre), 125 millilitres (1/8 litre) and – I just checked in my shed – even 375 millilitres (3/8 litre).
All sizes are written in either litres (for a litre or more) and in millilitres (for less that a litre). There are no vulgar fractions, and there are no decimal fractions listed on any of my Australian paint cans (small sample of 9 cans). Clearly the paint makers have decided to use the metric system but they have yet to discover the decimal metric system of 1793!
'Where modern economics would alter the price, the usual practice before the seventeenth century was to change the size of the measure. Candy bar manufacturers do the same today, because people associate a particular price with a particular candy and less resentment is caused by shrinking the bar than increasing the price. Fear of riots in the streets forced the Vatican city authorities in the fifteenth century to require bakers to sell loaves of bread at a fixed price, increasing the size when flour was cheap but reducing it when flour was dear. In thirteenth-century England, the king permitted bread sellers to change the weight of a "farthing" loaf (a farthing was a quarter of a penny) but not the price, and similar legislation on bread prices and sizes was in force in cities across Europe'. Andro Linklater, 'Measuring America', Walker and Company, New York.
Han Maenan, from the Netherlands and Tom Wade, from Eire, led a discussion on the USMA* mail list about carpet prices in Ireland (Han visits there regularly). There is apparently some reluctance for Irish carpet sellers to convert to prices in square metres. As Tom put it, 'The problem, of course, is that price per square yard looks cheaper'.
I replied, 'Have you used the '10 – 11 – 12 – 13' rule for conversions that is based on these approximations:
- 10 metres is about 11 yards,
- 10 square metres is about 12 square yards,
- 10 cubic metres is about 13 cubic yards.
As you can see, the square yard prices of carpets would be almost 20 % lower than the square metre prices.
* You can find details of the United States Metric Association discussion list at: http://lamar.colostate.edu/~hillger/listserv.htm
8 Rule of thumb
- An average baby is 3.5 kilograms at birth;
- Small babies are about 2.5 kilograms; and
- Big babies are about 4.5 kilograms.
Whatever its size the baby will double its birth mass in six months; for example, a 3.5 kilogram baby at birth, will be about 7 kilograms at 6 months.
Traders have always known that having a range of measures offers the best opportunities for cheating their clients. From earliest times, people who used false measures have been denounced by religious and government authorities.
- The Koran says: 'Woe to those who stint the measure. Who when they take by measure from others, exact the full, but diminish when they measure to others, or weigh to them.
- The Jewish law in the book of Deuteronomy says: 'Thou shalt not have in thy bag diverse weights, a great and a small.
And the Old Testament uses measurement as a running theme:
- Shall I count them pure with the wicked balances, and with the bag of deceitful weights.
- A false balance is an abomination to the Lord; but a just weight is his delight.
- Diverse weights and diverse measures, both of them alike are an abomination to the Lord. and,
- But thou shalt have a perfect and just weight, a perfect and just measure shalt thou have, that thy days may be lengthened in the land which the Lord thy God giveth thee.
The commonest way to cheat was, and still is, to use two sets of mass and volume measures, a large one for buying, and a small for selling. Many modern traders use the metric system to buy, and then sell using any old units that the public will accept.
10 Hidden metric
When the 200 litre oil drum was designed it allowed for 200 litres of oil plus a small airspace. When this drum arrived in Australia and the UK, it was measured and found to contain about 44 Imperial gallons; so it has been know in those nations as a '44' ever since. When the same 200 litre drum arrived in the USA it was measured and found to contain about 55 USA gallons, so in the USA the 200 litre drum has always been called a '55'.
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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