Metrication matters - Number 19 - 2004-12-10
Metrication matters is an on-line metrication newsletter for those actively involved, and for those with an interest, in metrication matters.
If you know someone who might benefit from this newsletter, please forward it to them and suggest they subscribe. If a friend sent this newsletter to you, please check free subscription details at the end.
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
Bruce Raup, from the National Snow and Ice Data Center, in Boulder, Colorado, correctly pointed out that I made an error when I said that a 'cubic metre of air had a mass of 1.2 kilograms' when I hadn't clearly specified the location of the air. Bruce remarked:
Obviously, if you moved a cubic meter of air (as measured at sea level) to Boulder, its mass would not change (its expansion would compensate for its lower density) . . . if you simply move a 1 cubic metre parcel of air (at 101 kPa) to Boulder (83 kPa), its volume would be 22% larger (101/83 = 1.22 m3) (assuming the temperature doesn't change), but its mass would be unchanged (1.22 kg), since the number of molecules has not changed.
Christoph Oelke, from the Institute for Geophysics at the University of Münster, joined this discussion by calculating the mass of a cubic metre of air at sea level in Geelong (1.2256 kg/m3) and at 1700 metres above sea level in Boulder (1.0040 kg/m3).
It seems that one kilogram of air in Boulder has a mass very close to one kilogram. When I shared this information between these two scientists, Bruce Raup wrote back to say:
Christoph and I used to have long discussions about the metric system and the state of American metrication when we shared an office. Small world.
Later, Robert H Bushnell, who lives in Boulder Colorado, confirmed these calculations when he wrote:
I tell people the mass of air in a cubic metre 'right here in this room' is one kilogram.
Robert uses the value of 1 kilogram per cubic metre when he is finding heat losses due to infiltration in Boulder buildings when he is calculating amounts of solar heat for buildings.
Many new students are now enrolling for the 'Metrication Basics' e-course. If you would like to join them, go to:
Through the coming together of a number of favourable factors – like the relative strength of the Australian dollar – I figured that it might be possible to visit the USA during the middle part of 2005. I have not visited the USA since the early 1980s. When I investigated further it became apparent that, for not much extra, I could travel around the world rather than going to the USA and back.
My current planning revolves around (sic) a 'Round World' ticket that will allow me to visit the BIPM and London on the way to NIST and the Smithsonian in Washington DC before I get to California on the way home.
I am currently going through the exhilarating task of trying to work out the places I would like to visit, and when. As I would really like to meet as many fellow metric enthusiasts as possible, please let me know if you would like me to consider planning to travel to your town or city, and I will see if I can incorporate it into my plans.
Needless to say I am very excited about this opportunity.
Recently, the world's largest bottle of wine was auctioned by Sotheby's in New York. This giant bottle called 'Maximus' was moulded and blown by Czech craftsmen and glassblowers. Maximus has a capacity of 130 litres, which is equivalent to 173 bottles or 1152 glasses. See the Radio Praha web page at: http://www.radio.cz/en/article/60696 for photographs and further details.
Maximus is 1.37 metres high; its diameter is 436 millimetres giving it a circumference of 1.38 metres. Maximus was filled with Beringer Private Reserve Cabernet Sauvignon (2001 vintage) from the Napa Valley. When auctioned the Maximus bottle of wine sold for $56 000.00 USD.
1 millimetre is about the thickness of an Australian 5 cent piece; or in the USA it is the thickness of a dime. Other approximations that are useful in learning to visualize millimetre measurements are:
- 10 mm is about the width of a woman's little finger.
- 10 mm is about the width of a man's little finger nail.
- 15 mm is about the width of a man's thumb nail.
- 20 mm is about the width of a woman's thumb.
- 20 mm is about the diameter of an Australian 5 cent coin.
- 20 mm is about the diameter of a Jefferson nickel.
- 25 mm is about the width of a man's thumb.
- 30 mm is about the length of a small paperclip.
- 80 mm is about the width of the palm of a woman's hand.
- 90 mm is about the width of a woman's fist across the knuckles.
- 90 mm is about the width of the palm of a man's hand.
- 100 mm is about the width of a man's fist across the knuckles.
- 150 mm is about the length of a Bic Pen with the cap on.
- 200 mm is about a woman's hand span.
- 200 mm is about the width of office paper – A4 is exactly 210 mm and US Office is about 216 mm.
- 300 mm is about the length of office paper – A4 is exactly 297 mm and US Office is about 279 mm.
- 500 mm is about the width of a filing cabinet.
- 800 mm is about the width of a door.
- 1000 mm is 1 metre.
- 1200 mm x 750 mm is a small dining table; 1500 mm x 900 mm is a medium dining table.
- 2000 mm is 2 meters or about the height of a door.
5 Signs of the times
In his book, Clear Waters Rising – A mountain walk across Europe – Nicholas Crane recorded the information he saw on a roadside.
Clear Waters Rising – A mountain walk across Europe Copyright (c) Nicholas Crane, 1996 All rights reserved PENGUIN BOOKS
Leaving Azpeitia I passed an old cast-iron signpost indicating the distance to three villages, accurate to three decimal places. Regil was 9.143 kilometres from where I stood, Vidania was 15.269 kilometres, and Urrestilla was 2.907 kilometres. Why should anyone need to know how far it was, to the nearest metre, to these villages?
Those of us who know that we walk at about 100 metres per minute could use this information to know that walking to Regil would take 91.43 (say 92 minutes); Vidania would take about 153 minutes; and Urrestilla would take 29 minutes. Of course, in guessing a speed of 100 metres per minute, I have made an assumption that these paths are on more or less level land; but I suppose that a book with the sub-title, 'A mountain walk across Europe', suggests otherwise!
David Shatto from the Institute of Geophysics and Planetary Physics at the University of California passed on this item (shortened here for quick reading) from:
Lunar Robotic Village,
Moon Base Gains International Support
As Moon exploration looms larger among the growing community of scientists and engineers from Europe, India, China, Japan, and the United States, a robotic lunar village is gaining support, leading to a permanent human presence on the Moon by 2024.
'A new lunar decade has begun', states a declaration crafted by the member nations who participated in a major lunar conference held last week in Udaipur, India. That gathering involved some 200 scientists from 17 countries, with experts focusing on new and planned missions to the Moon as well as plotting out concepts for long term exploration of the Moon and utilization of lunar resources.
. . . The Udaipur Declaration specifically recommends several steps: (that include) Coordination of international efforts for the establishment of 'standards' to facilitate lunar exploitation and settlement, e.g., use of the metric system; ...
Wow – a 100 % metric moon! With luck it could be contagious and spread to the Earth.
How much does it cost to change to metric measurements?
From my own experience metrication does not cost anything; it saves money.
After the initial, relatively small, expense for planning and training, the rest of the metrication program is about counting the savings and the profits.
Remember that metrication is a one time expense, but not going metric is an on going expense that goes on year after year (after year, after year, after year – if you require dramatic effect for your next pro-metric speech).
However, despite all the positive experiences in every country in the world, this question has not been well researched.
To help you develop your own thoughts on metrication costs, here are some rhetorical questions adapted from notes on the United States Metric Association (USMA) mail list (The principle contributor was 'Euric'). See http://lamar.colostate.edu/~hillger/listserv.htm
- How much it has cost us for not being metric.
- How many businesses have lost orders or contracts because they could not do the job in metric?
- How many have made costly mistakes in converting a metric job to old measures?
- How many have had to pay a premium for metric parts because they only bought enough for a specific job?
- How many people have had to be terminated because they refused to work in metric? How much does it cost to find and employ their replacements?
- How much does it cost to retrain school leavers in old measures when they have been taught the metric system at school?
- How much has not going metric really cost us?
In addition these three stories about costs might be useful.
- My experience with metrication in the building industry in Australia suggests that a well-planned and well-executed metrication program will increase gross profit by between 15 % and 20 % leading to net profit increases between 10 % and 15 %.
- In General Motors when they began their metrication program (in the 1970s) they created a group to monitor the costs so that they could claim them back later from the government. Then, when they discovered how much metrication was saving their company, they quietly disbanded the metrication costs accounting group.
- The Confederation of British Industry (CBI) surveyed its members about metrication in 1980, after 15 years of British metrication. They concluded that the companies who were still using dual measuring methods were about 14 % worse off in gross profit and about 11 % worse off in terms of net profit when compared to fully metric CBI companies. The Confederation of British Industry was established in 1965 by combining the former Federation of British Industries (founded in 1916), British Employers’ Confederation, and National Association of British Manufacturers. It is a confederation that acts as a pressure group promoting the interests of the UK's larger businesses.
8 Rule of thumb
Lightning travels through the Earth's atmosphere (the 'speed of lightning'?) at about 18 000 000 000 m/s, which is 18 gigametres per second. In mixed units this is equivalent to 5 gigametres per hour, or 5 million kilometres per hour.
If the hair on your arms and head start to stand on end, the lightning is going to strike near you. Get as far as you can from any trees then squat down with your feet as close together as possible. If you can't balance on your feet, drop to your knees and lean forward. Put your hands on top of your knees to avoid the ground current that can occur if the lightning strikes within 50 metres.
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
In the 13th century, England made another attempt to standardise units of measurement some of which were intended to have decimal relationships such as 100 fathoms in a furlong and ten furlongs in a mile. Henry VI's advisers changed the developing decimal system in England back to non-decimal methods, somewhere around 1440. More complicated units have, throughout history, often replaced simple measures, presumably for commercial reasons. No other attempts were made to decimalise English measures until the English gallon (4.536 litres) was defined, in 1824, as 10 pounds (4.536 kg) of distilled water.
10 Hidden metric
Harry Wyeth pointed out that even under water metric measures can be hidden. He wrote:
As a scuba diver, we are taught in the USA that pressure doubles at 33 feet, that at 66 feet there is another atmosphere of pressure added, same at 99 feet, etc. These are clearly references to depths of 10 m multiples. In diving, it is pretty easy to visualize. If you are 30 metres down (which is about the limit for recreational diving), the water pressure is four times more than the pressure at or just below the surface. It also means that your air regulator is supplying your air at a pressure four times that of surface pressure (hopefully!).
Please contact for additional metrication articles and resources on commercial and industrial metrication'.
Is it possible to arrange a gift subscription to 'Metrication matters'?
We know that this is a popular feature of many e-newsletters, but we have some problems with this because it is in conflict with our privacy and anti-spam policies at 'Metrication matters' (see below).
We also know that as subscriptions to 'Metrication matters' are free, it's hardly an expensive present, but I guess it's the thought that counts! Remember that as your 'gift' is to provide them with the 'Metrication matters' link. What you could do is to send a covering letter to your friend that is something like this:
I have been enjoying reading a free monthly newsletter called 'Metrication matters' for a little more than twelve months, and I thought that you might enjoy it too. Just log in at:
There are links on the sign-up page to the back issues of 'Metrication matters' so you can check if they are right for you before you sign up.
Subscribe to Metrication matters - it's FREE