Dear John, I have interspersed some answers, and some comments.
on 2003-09-06 06.07, john mercer at [EMAIL PROTECTED] wrote: > Hello everyone I just want to thank everyone for answering all my questions. I have to say that I am no longer surprised by the generosity of the members of the USMA mailing list. > I have another couple of them. How many Hectares are there in a square > kilometer? There are 100 hectares in a square kilometre, but it is rarely necaessary to do this conversion. If you are measuring city blocks, you use square metres and don't worry about the size of the numbers. If you are measuring farm land, you use hectares and you don't ever try to convert them either to square metres or to square kilometres. If you are measuring the size of a state or of a country you use square kilometres, but you should never have to convert to the smaller area measures. [If the country is large, such as Australia or the USA, you might find that square megametres are more convenient.] By the way hectares is usually spelled with a lower case 'h'. > If a person asks me how many Cm's are in an inch should I tell them > 2.5 or 2.54? I know that 2.54 is the exact conversion but is 2.5 good enough > for every day use? If a person asks me 'how many Cm's are in an inch', I tell them that I never use centimetres or inches. I then ask why they want to know, and then we can discuss what are the appropriate SI units for their task. In doing this I try to get around the idea of conversion from one unit to another � it seems to me that conversion always leads to a dead-end. > If I explain the metric system to someone who isn't used > to it and wants to know the conversion factor I don't want to make the metric > system seem dificult. The metric system is not difficult � most people can learn it in a few hours. The difficult part is for anyone who 'wants to know the conversion factor'. > I know that Usma doesn't support conversion because it > can make the metric system seem mor dificult than it is. It's in the conversion process that most difficulties lie. It is not true that the conversion factors make the metric system seem more difficult � the metrc system is always simple � but you can't even see the metric system if all you are looking at is conversion factors. The ideal is to move to the higher ground of the metric system without getting bogged in the 'conversion factors' marshlands. > However when we > explain the metric system using a measurement they are used to it might help. This is entirely contrary to my experience. And believe me when I say that I have tried to use conversion factors to help people make the metric transition � it was a total waste of my time and the time of the people I was trying to help. > I agree having dual sided rulers and meter sticks only slows the progress of > going metric. Thanks again for all your help John Mercer. I don't know if you have seen this piece that I wrote about the 'Ways to go' to metrication. [If you have seen this, please excuse me reposting it. Ways to go � Pat Naughtin 1 The Worst Way To use this method, you essentially aim to use 'hidden old units'. Let me explain how to do this. Firstly, you convert all the old values in your work directly to metric, eg. if one of your spare parts requires an 18 inch component, you call this a 457.2�millimetre component, or a 45.72 centimetre component, or better yet you list both 457.2�mm, and 45.72�cm, and 18�inches, and 1' 6" in your catalog. Secondly you provide all of your staff with extensive conversion charts and booklets (that include the 457.2�mm value as well as some 69�432 others � 69�427 of which your staff will never use!) designed to fit neatly in the bottoms of desk drawers and to paste firmly on the insides of office cupboard doors � in these positions these charts and booklets can delay your metrication program for many years. These two simple techniques should delay metrication by upwards of 100 years and they should cost the company heaps as they are clearly based on the idea of giving an illusion of metric progress while we retain our individual mindsets. Regard 100 years as the absolute minimum for this path. Consider the New York Stock Exchange as an example; by hiding the new (in 1793) decimal currency behind the old (in 1792) 'pieces-of-eight' in quoting stock prices, they were able to delay decimalisation from 1793 until 2001 � a delay of 208 years � very impressive. Think also of the oil industry's barrells and you will begin to see the delays that are possible. 2 The Nearly Worst Way This technique places its trust in dual measurements. You supply all staff with dual sided rulers and tapes, and copious quantities of conversion charts. You insist that all documentation is done using dual measurements, although it is rare for companies using this route to specify which takes precedence presumably on the basis that the random generation of precedence by each member of staff is the best policy for the company as it gives each member of staff freedom of choice. You can probably plan for this technique to take your company around 75 years to 100 years for its conversion. As an example consider the Kodak company who made their decision to use 16 mm B&W film in 1910 and 16 mm color movie film in 1929; they also decided to use photographic paper based on 10 inches by eight inches sizes with multiples and sub-multiples of this inch size. This dual measurement has delayed metrication at the Kodak company for 93 years so far, but in 2002 they began yet another metrication effort � they might make the transition within the 100 years I suggest for this technique. 3 The Second Best Way Use centimetres. This way you can keep those lovely fractions in your vocabulary. Remember that using millimetres exclusively, almost completely removes the need for fractions (together with their attendant extra time and costly errors). Do not form a company-wide measurement policy � let each department form their own. In this way the manufacturing departments will eventually use millimetres as others do in their crafts; the office staff will eventually use inches and centimetres � as others who sew and knit use these measures; the sales staff will change their measures according to how they see their customers in terms of conservatism/progressiveness � in any case the sales staff often don't really care to know about measures (other than sales figures at the end of the month). It's hard to guess how long this pathway takes. I have direct experience of the textile industry in Australia and they are still struggling (while making snail-like progress) with metrication after 30 years � my guess is that it will take them at least another 20 years, so my estimate for the 'Second Best Way' is between 50 and 75 years. 4 The Best Way Use other people's experience. Find out where metrication has been successful anywhere in the world and simply copy their techniques. Form a measurement policy � by saying things like 'Of all the length measures available in the metric system, our company has chosen to use millimetres, metres, and kilometres' and 'The centimetre will not be used in calculations and they will never be written down'. 'It is the policy of our company to use rounded metric values of components wherever we can � we believe that this will lead to a simplicity that will reduce errors in production, administration, management, and sales'. These quotations are adapted from Australian building literature of the 1970s. Using this technique the whole of the Australian building industry had essentially metricated in under a year, and if you count the laggards, definitely had completed the process in under two years. It seems to me that Industrial Heating Magazine has clearly chosen the 'Nearly Worst Way' to metrication � I wish them well � but there's no need to put the champagne on ice just yet, it's a long time till 2103. Cheers, Pat Naughtin LCAMS Geelong, Australia Pat Naughtin is the editor of the free online newsletter, 'Metrication matters'. You can subscribe by sending an email containing the words subscribe Metrication matters to [EMAIL PROTECTED] --
