Metrication matters - Number 12 - 2004-05-10
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
Today 'Metrication matters' is a year old and I would like to hear some comments from you to guide future developments. If you have a few minutes could you answer these three questions?
- Which topic is the most useful to you?
- Which topic is the least important?
- Have you have any suggestions for new themes for 'Metrication matters'?
Thanks for your help, and for your time.
I had a good response to my request for information about puttonyos (and everyone who responded won first prize!), but I am now somewhat embarrassed that I raised the question in the first place. I got sucked in to the fascination of the history of this old unit, when I should be concentrating on 'Metrication matters' rather than the history of bizarre old measures. Sorry about that. I will behave myself in future.
By the way, a puttonyos is the name of a basket for carrying grapes in the Tokaji region of Hungary. These grapes are then made into dessert wines such as Tokaji Asz˙ (pronounced TOK-kay OS-soo). Tokaji Asz˙ is truly one of the greatest natural dessert wines of the world. The grapes have a condition known as Noble Rot and if it takes three baskets to make a barrel of wine, the wine is said to be a '3 puttonyos' Tokaji Asz˙. It is possible to buy wines of 3, 4, 5, and 6 puttonyos. The minimum age at which they should be drunk is their puttonyos number plus two. Louis XV of France (1723-1774) offered Tokaji Asz˙ to Madame Pompadour with the following words "C'est le roi des vins et le vin de rois." (This is the wine of kings and the king of wines). Tokaji Asz˙ was first made in the 1560s.
Notice how I neatly skirted around the sizes of the baskets and the barrels; this is because I have no idea of the size of the barrels, or for that matter of the puttonyos (baskets). All I know is that the Tokaji Asz˙ must be matured in barrels - not just any old barrels - but barrels that are at least twelve years old that are made only from the oak trees of the Zempleni forest. So know you know about puttonyos, but I can't see how this research has helped the world move more rapidly to metrication.
As every individual, group, company, and nation goes through their metrication process, there are pockets of hard-line resistance to metrication. Some of these don't matter much as they effect only a small group of people - the quarter mile 'rev-heads' in Australia are an example of this. However, other hard-line metric resisters can have an effect that is much greater. For example, the Avery Label company seem to have an pro-inch policy that is all pervasive and it forces everyone in the world who uses their labels to have to learn about the bizarre old imperial measures. In turn, the computer software companies design their word processors to accommodate Avery labels and on goes the imperial madness in every business that uses mailing labels.
Another area of resistance to metric measures is amongst the quilting community, where layout boards and rulers are set out in inches. It soon becomes obvious why this is so, when you realise that there is a lot less sewing in a quilt with two inch squares (50 mm) than there is in a quilt with (say) 15 mm squares. However, some would say that the results look rather chunky.
If you want to measure down from the ceiling to (say) a window sill, use a stick to hold the little clip on your builder's winding steel rule so you can push it up to the ceiling without the tape bending.
5 Signs of the times
Over the last few days, I have been hearing excitedly breathless reports about the 'Gravity Probe B' space mission. Sadly, all the data I heard on radio was in old inch-foot-pound measures.
- the craft is to fly at 400 miles high
- the gyroscope sphere was to be an almost perfect 1.5 inches diameter (when it wasn't 'about the size of a golf ball)
- if the gyroscope was expanded to the size of the Earth its biggest bulge would be 8 feet
- the Dewar flask to contain the science module is 9 feet tall
- the Dewar flask holds 645 gallons of superfluid liquid helium
I suspected that the radio stations were simply reporting directly from a NASA site, and sure enough, I found it at:
It amused me somewhat to see this line:
'If Albert Einstein were alive today he'd be relaxing in his easy chair, pipe in hand, very calmly awaiting the results of this historic mission and probably marvelling at the technology it takes to probe his 89 year-old theory'.
Perhaps, what they meant to say was:
'If Albert Einstein were alive today he'd be "frantically worrying " while . . . awaiting the results "(he couldn't possibly know who was doing what conversions, from what old measures, with what conversion factors, and with what errors)" of this historic mission and probably marvelling at the technology "(at least wondering how NASA could possibly produce such advanced technology when they are clearly dedicated to the encouragement of seriously old and proven difficult-to-use measures)" it takes to probe his 89 year-old theory'.
Let us hope that the remaining components of this mission aren't equally suffering from the same mish-mash of old and new measuring units that led to the loss of the Mars Climate Orbiter. Admittedly one of NASA's suppliers, rather than by NASA's own engineers, made the error that caused the loss of the Mars Climate Orbiter.
I can only hope for the best for this extremely important mission, as quiet confidence in sound technology, well applied, is clearly out of order given the above context.
It is India that gave us the ingenious method of expressing all numbers by means of ten symbols, each symbol receiving a value of position as well as an absolute value; a profound and important idea, which appears so simple to us now that we ignore its true merit. But its very simplicity and the great ease which it has lent to computations put our arithmetic in the first rank of useful inventions; and we shall appreciate the grandeur of the achievement the more when we remember that it escaped the genius of Archimedes and Apollonius, two of the greatest men produced by antiquity. Pierre-Simon de Laplace, (1749/1827) In H. Eves Return to Mathematical Circles, Boston: Prindle, Weber and Schmidt, 1988.
Question: Are you quite certain that unit symbols should only be used after numbers? I would appreciate it if you could point out where this is documented.
Answer: In answering this question, I am relying on a well-written reply that Bill Hooper from Fernandina Beach, in Florida, USA shared with the United States Metric Association (USMA) mailing list. Bill said:
'I think this is as much good written style as it is a "rule" of SI. Generally symbols and abbreviations are used only in specific situations, not as general replacements for words in ordinary sentences. Perhaps I can illustrate this best with a series of examples.
'Just as you should write:
- "I went to see the doctor today", NOT "I went to see the Dr. today"; and
- "The value of the dollar has declined", NOT "The value of the $ has declined"; and
- "There are palm trees at the Florida border", NOT "There are palm trees at the FL border"; and
- "He continued down the street", NOT "He cont'd down the street", (or worse yet "He cont'd dn the st.");
... so also, you should write:
- "This is a kilogram scale", NOT "This is a kg scale"; and
- "How many millimetres long is that?" NOT "How many mm long is that?" and
- "Volts are the units of electric potential", NOT "V are the units of electric potential"; and
- "The satellite's altitude is hundreds of kilometres", NOT "The satellite's altitude is hundreds of km", (or worse yet, "The satellite's alt. is 100's of km.").
The following are PROPER uses of the abbreviations and symbols used in the examples above:
- "Good morning, Dr. Becker." (title as part of a name)
- "That costs $25." (dollar sign used with numbers)
- "This part is 45 mm long." (millimetre symbol used with numbers)
- "He lives in Miami, FL". (state abbreviation used as part of an address)
- " ... and the police said the driver was not at fault, but they had to (cont'd pg. 5)" (at end of a page)
- "There were 10 kg of potatoes in that sack." (kilogram symbol used with numbers)
- "The potential between the poles of that motor is 12 V too high." (volt symbol used with numbers)
- "The satellite's altitude is 250 km or perhaps more." (kilometre symbol used with numbers)
By the way, Bill Hooper signs all of his emails with this note:
Make it simple; Make it Metric
8 Rule of thumb
A useful start to a worm farm is to use 10 000 worms per square metre (about 2.5 kg/m2). Plan your worm farm to be up to 150 millimetres deep and to have a capacity of 15 litres for each member of your household. A worm can eat its own body mass in food each day. A kilogram of worms (between 3000 and 4000 individual worms) will eat about one kilogram of food scraps every day. Earthworms travelling to new food sources have been tracked for distances of up to one kilometre. Native earthworms of south-eastern Australia can grow to 2.5 metres long and 30 millimetres thick.
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 1660, the Royal Society in London suggested that a universal measuring system should be based on the uniform length of a pendulum that swung uniformly back and forth in one second. A metre that was defined as the length of a pendulum oscillating in two seconds (one move per second) was eventually dropped because of two main difficulties. There was the problem of measuring the exact length of the string from the point it was suspended to the centre of the ball and the gravitational forces are not uniform all over the Earth. On its own the difference in gravitational forces leads to a metre that is 5 to 11 mm shorter than the metre we use now.
As an alternative to the pendulum Gabriel Mouton, in 1670, came up with the idea of a decimal unit system using part of the circumference of the Earth as a standard for measuring lengths. He suggested that Simon Stevin's 1585 system of tenths should be used to divide the units into smaller or larger parts.
In 1675, an Italian, Tito Livio Burattini, actively promoted the length of a pendulum that beat seconds as the universal unit of length. He referred to this unit of length as a 'mŔtre catholique' or a 'mesure universelle'. Burattini was the first person to suggest the name 'metre' as the name for the common unit of length.
Eventually it was decided to use Tito Burattini's name for a metre based on Gabriel Mouton's idea of using the Earth as a basis of its length, and to divide it decimally as suggested by Simon Stevin
10 Hidden metric
Jewellery buyers all know that gem stones are numerically fattened by the use of a carat dangled before their eyes. A carat is defined as 200 milligrams, so a five carat diamond has a mass of exactly one gram. But a five carat diamond sounds a lot bigger than a one gram diamond don't you think - even if they are both the same size.
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.
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