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The ultimate reference: Bureau de International des Poids et Measures
 

On 11/6/2002,  Donald Lang summarised the discussion:

Any topic that can generate a couple of dozen messages and over a cricketting ton of  KB in about a day must be tapping into a few atmospheres of steam. At a guess there are several issues. The one that I suspect will go on longest and with most misery is the spare parts thingy. The broken window is the token. Glass for fitting snugly into the old ones is going to be more difficult to find. Matching pipes if a length rusts out, etc. People at the fringes of fame may go on breaking athletic records for imperial distances for quite some decades. I suspect that not too many members of the list know how far along they are in eating "a peck of dirt" during their lifetime.

Heights and weights, stature and mass, [of those we meet] are possibly where most people have their best precision estimates. It is inconvenient to learn the same precision in unfamiliar units. New units, like new theories, may have to become familiar over a lot of dead bodies.

 Away from personalities it becomes easier.Having been brought up in imperial units I equate yards with metres if making shoddy estimates of distance. If I guess how heavy something is, not a person, in pounds, I can divide by two and get a fair estimate in kilos. I don't think in terms of so many stone for people any more.

George Orwell noted in "1984" that putting beer into metric measures was inconvenient. Hectares are convenient for some things and not for others. Measuring either in square metres or square kilometres is inconvenient if you are unhappy with "scientific" notation. Some of my electronics friends are 'nearly' serious in quoting the speed of light as ONE [foot per nanosecond]. Before the fine structure rebelled, light speed was also something like eighteen megafurlongs per microfortnight, give or take any necessary powers of ten. It is true now that all distances, including the metre, are defined by means of time, eventually. It is a little difficult to play with the astronomers who insist on measuring large distances in angles.Between the parsec and the AU lies the light year, coming down steadily with distances measured in months, days, hours, minutes and seconds. Good road maps show distances in times. Commuters think the same way. The tank on my car holds a greater range when the engine is properly tuned.... Explorers can come unstuck if they get their supplies wrong. The proper measure of terrain may be in days of travel.

There is some moderately serious stuff somewhere about here. A decade or so ago, it was noted that in addition to a diversity of languages, Papua /NG had a considerable number of counting schemes.. You could imagine that children brought up to count by dozens or whatever other base would find some of arithmetic a lot easier. I think I heard that this was true for those who were the sort who learn easily how to skip from base to base whatever their starting point.  For most of the population, having to dismantle your counting system was just an an additional pain. The SI unit of pain is called a millstone. People from some language groups were found to be carrying at least a microstone into their mathematical studies, on average.

In the matter of currency, Peter has pointed to the former fun in which there were 5! [five factorial] pennies in half of a pound. Mathematicians might dismiss this as a Sterling approximation.

Of course new units will continue to crop up. For example I am sure there are a few list members whose driinking habits are now calibrated in units to the base 0.05.

Me, I was educated in older units. I think I will retire to bed with half a gumboot of cooking drambuie.

ttfn

DEE

At 09:31 PM 10/08/2002, Tony Legg wrote:
>
> Anyone notice that the sizes of ready-made picture and photo frames are  still quoted in inches? eg 14 x 17? With or without > a conversion to centimeters.
>
> Tony
 

what's really screwy is that those sizes only really work for 2" negs.

35mm negs don't fit into 10x8 or 14x11 or 20x16 easily, there's heaps of cropping involved.

how's that for stupidity?

kaz

so are TVs, Vinyl Records and Penises.

I was bought up with metric but can never see a persons height in CMs only feet.

Wolfie!
 

> I haven't measured anyone's stature (the scientific term for height) other
> than in m (or cm) for about 25 years. And in that time I have measured the
> stature of hundreds of service people.
>
> The standard screening test throughout the world for weight category
> ('underweight', 'normal weight', 'overweight' or 'obesity') is based on body
> mass index (BMI). BMI is calculated as weight (kg) divided by
> height-squared, where height is in m.
>
> Underweight is defined as BMI >18.5
> Normal is 18.5-24.9
> Overweight is 25.0-29.9
> Obese is 30.0 and above.
>
> Chris Forbes-Ewan

I do prefer metric currency though. Bloody Guineas, Pounds, Shillings, and Pence were a nightmare to work with.

Bill (the Ludite) Miller

Forbzy said:
 

>  Just because  you are more familiar with the former concept (thinking in terms of the  distance travelled first and the quanity of petrol used second) you are  making the mistake of assuming that this is somehow more logical--it isn't.   To someone from Europe who is used to thinking in terms of 'petrol first,   distance second', this would seem more logical. It simply depends on your  point of view

If measuring speed of a motor vehicle it is logical to use distance per unit of time and most rates are expressed that way, ie.  with time as the base of measurement.  But discounting time as the base for rate measurement, there are other rates for derived units but scanning a list of them, there is no precedent for expressing rates with any particular base.

However, there several reasons why it is illogical to use L/100km as a measure of fuel economy.

Firstly, and self-evidently, the abbreviation is cumbersome.  There is a perfectly good measurement in kilometres per litre, which

I put the alternative point of view that, it is only because the Europeans have made so many mistakes with measurement like using factors of 100 in units, that the system is now so difficult to use.

Secondly, because it was such a change it has never caught on.  Apart from motoring writers who are probably just reprinting the information provided to them anyway, the unit L/100km is hardly ever used.  Trying to introduce economy as L/100km establishes a new system of doing something which is not easily compared conceptually to what went before.  One of the lessons of the Australian metrification experience was learnt in a most costly way with poly pipe.  Don't change the concept of the measurement as well as the units.  But it was avoidable because a fundamental tenet of public education is to build on existing concepts, something learnt in Australian agricultural extension more than half a century before.

What is more, if you go to a car club you will find that members talk in distance per unit volume of fuel because it is easy to calculate a range using this measurement.  Most people I talk to about this are using km/L and I intend to keep doing that.

Thirdly, there is a similarity with speed which reinforces the idea that a rate should be a distance first.

So, we have given the metric conversion board (now defunct) a quarter of a century to impose the system it saw fit in the most high-handed way for us to have.  WRT to fuel economy it has failed and it is now time to do what should have been done in the first place, use kilometres per litre.

In summary, most things do depend, as you point out, on your point of view, but in this case, mine is correct and yours like the early views of the metrification board, while nicely theoretical, is not.

Toby

PS.  As a complete aside, have a look at any of the European porno sites - I am not an expert, but penis size in Europe, the home of metric, appears (in my sample) to be expressed comprehensively in inches.  It gives one some cause for thought as to why a foreign system would be used.  I am sure I could concoct (oops) a theory as to why, but I wonder whether using a measurement based on a body part to measure another has some inherent attraction.
 

On Sunday 11 August 2002 12:21, Forbzy wrote:
> Why is L/100 km 'dumb'?
>
Because some idiot decided to do things the opposite way for no good reason.

We don't measure speed by hours per kilometer but by kilometeres per hour.  Just about everything works that way.

Litres per 100 km is a purely artifical construct with no relation to reality.  100km is no an SI unit.  It is a multiple (by 100) of an SI unit and L/per 100km has no place in the SI measurement system

There are two good reasons why L/100km is 'dumb'.

On Sunday 11 August 2002 13:19, Forbzy wrote:

> There is no inherent logical superiority of km/L over L/100 km. Just
> because you are more familiar with the former concept (thinking in
> terms of the distance travelled first and the quanity of petrol used
> second) you are making the mistake of assuming that this is somehow
> more logical--it isn't.

It is however, more *consistent*.  And isn't consistency is what SI measurements are all about.
 

> To someone from Europe who is used to thinking in terms of 'petrol
> first, distance second', this would seem more logical. It simply
> depends on your point of view.

Not in that case.  In that case it depends on what you are used to *not* point of view.  L/100km is not consitent with other SI measurements.  Litres/km is halfway there.  Km./Lt is all the way there.

Anyway why are SI units a good idea?   Makes teaching numbers with different bases far, far harder.  What is wrong with furlongs per fortnight anyway?  At least it requires some mental agility.

Zero Sum

> > For example, quoting car performance in L/100km is dumb.  I know
> > all the (unconvincing) reasons why it was done, but in protest I stuck
> > with miles per imperial gallon for more than a decade hoping for
> > commonsense to prevail.  It didn't.  Like most others around here, I
> > have learnt over the last two decades to quote performance in km/L.
> > My car, when new did about 10.3km/L, but as I don't tune it unless
> > absolutely necessary, it now does about 9.2km/L.

>
> Why is L/100 km 'dumb'?

It may not be 'dumb', but it is easier to visualise things when one unit is expressed as '1'.

>
> That is the only way I express fuel economy and it makes the same amount
> sense to me that miles/gallon made 30 years ago. But because we have changed
> to SI units, I am happy to use L/100 km rather than miles/gallon (which has
> no official status in Australia now). And why would you use km/L when the
> correct unit is L/100 km? Are you the only soldier in the entire regiment
> who is in step? :-)

No he is not.  If the 'official' measurement is not user friendly then it will not be used.
 

> > But even now there is confusion about pipe classes, types and
> > fittings.  Now you might think this was not due to metrification,
> > but it is directly attributable to that change.

>
> I find that hard to accept. If people didn't adopt the change willingly,and
> confusion reigned, then it is the inflexibility of the people that was to
> blame, not the adoption of the most rational system of measurement ever
> devised.

Because it is a rational system, is not the same as saying it is the best system in all circumstances.  When working in timber a mm is too small a unit to easily work with. 1/16 the smallest measurement used in the imperial system was about as small as can be easily read off a (carpenters) rule. The divisions of an inch were also easier to read because the marked divisions were of different lengths.

Podargus
 

Me too: I still have trouble with 1200 by 2400 mm. What is strange because in Holland, where I come from, everything has been Metric since Napoleon. But .... hardly anybody used millimeters, but meters
and centimetres.
SO  ... 4 x 8' was 1.2 by 2.4 M, and a person's height might be !.8 M (6')
I know,  mm is the scientifically right way to do things, but I prefer cm, makes numbers not so terribly large

BTW I grew up metric, came here and had to learn imperial, then had to revert to metric again.
Well I had to, and now I usually can translate any length or weight etc from the one to the other, although furlongs etc escape me

Steve van Z

Some more non-SI units you may have forgotten

Measure of Weights 16 drams = 1 ounce 16 ounces = 1 pound 28 pounds = 1 quarter  4 quarters = 1 hundredweight
                                   20 hundredweight=1 ton=2240pounds

Measure of Area  9 square feet = 1 square yard    30.75 square yards = 1 square pole  40 square poles = 1 square rood  4 roods = 1 acre  4840 square yards = 1 acre  640 acres = 1 square mile
N.B. 1 Scottish acre = 6084 square yards , 1 Irish acre= 7840 square yards

Measure of Volume: 1728 cubic inch = 1 cubic foot   27 cubic feet = 1 cubic yard   42 cubic feet = 1 ton of shipping

Loads: Unhewn timber = 40 cubic feet  Squared timber = 50 cubic feet  1 inch plank = 600 square feet
            2 inch plank = 300 square feet

Imperial Beer Measure  1 gill = 8.665 cubic inches' 4 gills = 1 pint  2 pints = 1 quart  4 quarts = 1 gallon
9 gallons = 1 firkin   36 gallons = 1 barrel   54 gallons = 1 hogshead   72 gallons = 1 puncheon 108 gallons = 1 butt

The length of various miles, given in relation to the standard English mile, is given below. (All measurements are in yards).
Danzig 8475  Denmark 8244  Flanders 6864  Germany 6859  Hanover 11559 Holland 8010  Hungary 9113  Ireland 2240 Netherlands 1093  Poland 8010  Portugal 6760  Russia 1167  Scotland 1984 Spain 4639  Sweden 11700  Switzerland 9153

The following selection gives the local weight of a pound in relation to the English pound.
Amsterdam : 1.09 Antwerp : 2.205  Barcelona : 0.882 Copenhagen : 1.1013 Bremen : 1.099 Cadiz : 1.015
Cape Town : 1.09 Hamburg : 1.068  Odessa : 0.9026 Rotterdam : 2.205 Stockholm : 0.9365 Trieste : 1.235
 
 

. All values are taken from the Millwright and Engineers Pocket Companion by
William Templeton, published by Simpkin, Marshall and Co. London, 1865.
 

Clyde Gittins added
As I recall (South Qld)-
2 haypnies = a penny. 3 pennies = thrip'nce, or a thripny bit. 6 pence (or pennies) = a zac. 2 zacs = a bob, or a deener. 18 pence (often so called) = 1/6 (said 'one and six' or one shilling and sixpence). 2/6 = half a crown. 5/- (five shillings) = a crown. (I saw a crown once. I think it was issued to celebrate the opening of the Harbour Bridge?).

To bank cash takings, you had to roll the coins with pieces of brown paper provided for the purpose. Pennies had to be rolled in 5/- lots- 60 of them! The piece of paper was never big enough. You'd think you had it, and then the paper would slide off, pennies all over the floor. And just 5/- [50 cents] was heavy! Decimals were heaven after that.

The guinea was set at 21/- by Sir Isaac Newton, Comptroller of the mint. (Before then, the value fluctuated.)  [You may have thought he was knighted for his mathematics, but no -- he was an excellent civil servant.] It was a convenient unit for landlords: 3/- per day was 1 Guinea per week.

Clyde