Metrication matters - Number 57 - 2008-02-10
Metrication matters is an on-line metrication newsletter for those actively involved, and for those with an interest in metrication matters.
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I hope this email arrives when you are well, in good spirits, and that you feel that you are moving inevitably toward your complete upgrade to the metric system, in all aspects of your life.
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
Marion Moon, from the USA, sent me an absolute gem of a story. Marion wrote:
I know you deprecate vulgar fractions so, here is a good example why:
We had to have the garage door repaired. The Sears repairman told us that one of our problems was that we did not have a 'large' enough motor on the opener.
I thought for a minute, and said that we had the largest one Sears made at that time, a 1/2 horsepower. He shook his head and said, 'Lady, you need a 1/4 horsepower.' I responded that 1/2 was larger than 1/4. He said, 'NO, it's not.' Four is larger than two. We haven't used Sears repair since.
Jose Luis Barajas, from Mexico, wrote to send me this page reference.
This is fun.
I have to say that I thoroughly agree with Jose. I fell about laughing the first time I saw this short video clip and I'm still smiling broadly even though I have now watched it more than twenty times. Please pass it on to anyone you think might enjoy it.
Carleton MacDonald wrote to the USMA mail list to report on the measurement muddle on trains. Carleton wrote that all these statements come from a single Network Rail document:
The Track renewals team achieved good levels of output with 34.55 composite km of Plain Line track delivered. A total of 17 km of new wiring was delivered ... The remaining 3.5 miles of route were buried with turning chambers provided every 150 metres ... Additionally, some 2500 yards of plain line track was also re-laid ...'
And Martin Vliestra reported that:
Under EU law, all new car models must undergo standard tests that include acceleration, top speed, fuel consumption etc. It is surprising how many UK car magazines quote the time taken to reach 62 mph (without further explanation).
Han Maenen, from the Netherlands noted:
The 300 km/h of the Eurostar were converted to 186 mph that was back-converted to 299 km/h, and this ridiculous number has appeared in many English language news items. Now one can go on converting and back converting and in the end ... the Eurostar grinds to a halt!
The more I read about the history of the International System of Units (SI) the more I become convinced of the crucial roles played by Benjamin Franklin, Thomas Jefferson, and (less directly) by George Washington in promoting the idea that a reformed measurement system should be based on decimal numbers.
In the late 1700s, few of the French 'philosophes' had the extensive practical experience of using decimal numbers that was shared by these three men. Both Washington and Jefferson had been surveyors who used the decimal 'Gunter's Chain' in their daily measuring and calculation; they knew the value of using decimal numbers from direct experience. Franklin and, perhaps more so, Jefferson were both actively involved in promoting decimal numbers in the USA for currency, and in France as the basis for a universal measuring system during the 1780s, when both Franklin and Jefferson were, in turn, Ambassadors to France.
During a fraternity initiation ceremony at the Massachusetts Institute of Technology it was decided that a student Oliver R Smoot would be used as a 'standard' length for measuring the length of the Harvard Bridge. Smoot was laid on the bridge 364 times, and then the remaining bridge length was assessed as 0.4 of a Smoot. The bridge length was then reported as 364.4 Smoots and the precision was plus or minus one of Smoot's ears. Remember that, before the metric system almost all measurements used to be based on human body measurements — like the Smoot.
To determine the mass of something without scales, you can measure by spoon or cup. The drawback here is that different ingredients have different densities; this means that if you measure a cup each of flour and sugar using the same metric cup, you’ll have a lot more sugar than flour.
We checked a cup each of some of our more common cooking ingredients and our approximate results were:1 cup of plain white flour = 150 grams
1 cup of white sugar = 250 grams, and
1 cup of brown rice = 230 grams.
If you are using spoons and cups for your cooking you’ll need this sort of information.
Dipping a metric cup into a flour bag and leveling it by scraping against the side of the bag will give a tablespoon or two more than if you fill the cup with a spoon and level with a straight edge (a spatula or the back of a knife). The latter practice is recommended; the former is what many of us do!
This tip came from an Australian cookbook called Rice Village Cooks by Wendy Pomroy, so don’t forget that Australian cups are 250 mL; cups in the UK and in the USA are each different sizes!
5 Signs of the times
Recently we received a document from our state's Energy Efficiency Centre that advised us how much greenhouse gas was released every time we cooked a casserole. Each type of oven was listed, and the different emissions of greenhouse gas were depicted on a graph, with a caption that read:
Kilograms of greenhouse gas released when cooking a casserole.
The numbers on the graph were as follows:
- Electric oven 2.8 kg
- Electric fan-forced oven 1.9 kg
- Electric frypan or toaster oven 1.3 kg
- Gas oven 0.7 kg
- Microwave oven 0.5 kg
It seemed to me that this information would be made clearer if the writers had chosen to use grams instead of kilograms and to place the spelled out unit next to each number. The results would then read:
- Electric oven 2800 grams
- Electric fan-forced oven 1900 grams
- Electric frypan or toaster oven 1300 grams
- Gas oven 700 grams
- Microwave oven 500 grams
I think that this makes it easier to see that you produce more than 5 times more greenhouse gases when you cook with an electric oven rather than with a microwave oven even though there are now more trailing zeroes.
There are many opportunities like this for doing away with decimal, and vulgar or common fractions by the carefully considered use of the metric prefixes. When you use the metric system using the prefixes cleverly you might never need to have anything to do with common or vulgar fractions or even decimal fractions.
It's a bit like the argument about whether it is better to use centimetres or millimetres for measuring length. (See: http://www.metricationmatters.com/docs/centimetresORmillimetres.pdf )
Using whole numbers is of considerable help to people who have less developed numerical skills. I suspect that numeracy, like literacy, is much under-reported, and that there are many more innumerate people than we think.
Goals are dreams with deadlines.Diana Scharf Hunt
I love deadlines. I like the whooshing sound they make as they fly by. Douglas Adams
Why are wine bottles 750 mL? This seems to be an odd size given that a litre bottle might be better for a dinner party and 500 mL would be better for two people.
There are several explanations for the 750 mL bottle, including the culturally stereotypical idea that:
'750 mL roughly equates with about how much your average blue-overalled, moustachioed, Galoise-chuffing, French peasant could wolf down at a single sitting' (Australian Magazine 1999-07-10).
However, it is more likely that the 750 mL size is due to the technology of glass blowing, where 750 mL was a convenient size for a glass blower, given the pressure and volume that his lungs could produce.
Coincidentally, while I was researching this Q&A, I came across a reference to the wine drinking activities of Thomas Jefferson, who was one of the first people in the world to insist that his wine be bottled by the winery to prevent contamination or dilution by intermediaries. A Thomas Jefferson bottle of wine sold in 1985 for 105 000 English pounds (See: http://lafite-collection.antique-wine.com/tasting_notes.html )
8 Rule of thumb
Gene Mechtly from the University of Illinois wrote to say:
BMI is mass/(height)^2 in kg/m^2, not kg/m x 1/m That is not the same as kg/square meter of surface area, as your text (in Metrication matters 56) implies.
Gene is, of course, quite right in his criticism but I was trying to avoid the construction, 'kilograms per metre squared' that I find uncomfortable. I would appreciate reader's comments on this.
This leads me to the 'Rule of Thumb' that goes like this:
1 Think of your height in metres (say) 1.83 metres.
2 Remove the number '1' and the decimal point '.'
You are left with your ideal body mass in kilograms; in this case it is 83 kilograms. You could think of this as your:
3 Evaluate your current body mass by noting the difference between it and your ideal body mass.
10 % below this (83 – 8.3 = 74.7 kg) and you are underweight;
10 % above this (83 + 8.3 = 91.3 kg) and you are overweight;
20 % above this (83 + 16.6 = 96.6 kg) and you are obese;
30 % above this (83 + 24.9 = 107.9 kg) and you are very obese.
Those of you with an interest in music might be interested in the pianos made by Stuart & Sons in Newcastle, Australia who use the metric system in every phase of their construction. Currently, they have available a 2.2 metre Grand Piano and a 2.9 metre Concert Grand Piano.
Our interest in this piano goes back to the mid 1990s when my wife, Wendy Pomroy, collaborated with Wayne Stuart to edit his book, 'Piano Technology'.
I helped a little with the measuring part of the book and I recall a letter from Wayne about the use of the metric system in piano building in 1996. Here are some extracts:
Although Australia had adopted metric measurement before 1974, it was not until I studied piano technology that I actually began to appreciate its benefits.
I read an original copy of A Treatise on the Art of Pianoforte Construction by Samuel Wolfenden, published in 1916 by Unwin Brothers, London. The following lines from Wolfenden confirm the use of this system of measurement by experienced English piano makers despite a deeply conservative and imperialistic society. Wolfenden's treatise was written in his retirement and all measurements and calculations use the metric system.
"It is to be regretted that in this country (UK) and in the United States, this system has not been adopted. Its advantages become very obvious, when dimensions have to be multiplied, divided, or adjusted to proportion ... The millimetre is equal to a trace more that 1/25 of and inch, and the smallness of this has a beneficial effect on the mind and working habits.
"Many English rules are not marked with closer divisions than 1/8 of an inch, and a workman grows to regard this as a small quantity, and thus his sense of accuracy is impaired ... The only adaptation of the English rule which renders such calculations as are used in scaling fairly easy, is to divide the inches decimally and express all dimensions in inches and decimal parts; but even if this is done, the full metric system is much more convenient".
Western music and musical instrument technology has, for a very long time, had an international focus. Dominant European influence ensured dissemination of their version of science and technology. Piano design requires many long, tiresome calculations and measurements to establish the string scale and the most convenient system was bound to find favour.
Building pianos without the metric system would simply be much more of a hassle than it already is!
If you have any interest in metric pianos, you can find Stuart & Sons web page at http://www.stuartandsons.com/ and you can contact Wayne Stuart directly at
Coincidentally, 1916, the year that Wolfenden's metric piano book was published, was the same year that the United States Metric Association was formed (See: http://lamar.colostate.edu/~hillger/ ).
10 Hidden metric
While we are on the subject of pianos, it is interesting to see that the modern Steinway Model D piano is made 'to within fractions of a millimetre' and then sold as an 'eight-foot-eleven-and-three-quarter-inch' model. See: http://www.americanheritage.com/articles/magazine/it/1993/2/1993_2_34.shtml for details.
Pat Naughtin is a writer, speaker, editor, and publisher. Pat has written several books and has edited and published many others. For example, Pat has written 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.
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