Who 'Invented' Metric
Who 'Invented' Metric
(OP)
Does any body know how 'metric' came about.
I think the metre was supposed to be the circumference of the earth divided by 100,000 or something like that. But where did the kG come from and the Celcius.
We seem to have a real mish mash of units and knowbody sticking to them.
For instance, we have the kW for power as well as HP (Horse Power) and PS (Pferdestarke) which is a 'metric' horse power...(How can you have a metric horse power.)
I know that there is a thread on Metric already, but I don't think it was clear on who started it all. Any clues out there?
Sorry if this question has been raised already.
I think the metre was supposed to be the circumference of the earth divided by 100,000 or something like that. But where did the kG come from and the Celcius.
We seem to have a real mish mash of units and knowbody sticking to them.
For instance, we have the kW for power as well as HP (Horse Power) and PS (Pferdestarke) which is a 'metric' horse power...(How can you have a metric horse power.)
I know that there is a thread on Metric already, but I don't think it was clear on who started it all. Any clues out there?
Sorry if this question has been raised already.
Friar Tuck of Sherwood
RE: Who 'Invented' Metric
Try this link:
http://www.unc.edu/~rowlett/units/metric.html
and this one for more than you ever whated to know about any units of measure:
http://www.unc.edu/~rowlett/units/index.html
NozzleTwister
Houston, Texas
RE: Who 'Invented' Metric
The individuals who lead the field work were:
Jean-Baptiste-Joseph Delambre and
Pierre-Francois-Andre Mechain
Took them seven years.
If you like the combination of history and engineering, like I do, this magazine is the one to subscribe to. I have been with it for over 15 years - here is a link to the web site:
http://www.inventionandtechnology.com
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
The current official meter is x number of wavelengths of light emitted by excited krypton gas, though it used to be a fraction of the Earth's circumference along the prime meridian.
One cubic centimeter of water at 0°C(?) is one gram. 1 liter of water is thusly 1 kg.
Centigrade (Celsius) is set 0° for freezing and 100° for boiling at sea level atmospheric pressure.
http://www.EsoxRepublic.com
RE: Who 'Invented' Metric
<One cubic centimeter of water at 0°C(?) is one gram> ? 4°C?
Good Luck
johnwm
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RE: Who 'Invented' Metric
to be picky.
RE: Who 'Invented' Metric
meter = distance from equator to north pole (following the Paris' meridian, of course) divided by 10 millions.
Later they defined it as a length of a "prototype" kept somewhere like Sevres (town?) close to/in Paris. Then they tried to define it by the wavelength of some chemical element(?).
For a gram - we were taught in the school, that 1 kg = mass of 1 liter (= 1 decimeter cube) of 4 deg C water.
But since then the whole Europe changed n times, so I am not sure about anything anymore...
RE: Who 'Invented' Metric
Regards,
RE: Who 'Invented' Metric
Anders Celcius (see http://www.astro.uu.se/history/Celsius_eng.html) was a scientist in eighteenth century Uppsala, Sweden. He used freezing and boiling water as fix points on his thermometer scale. He divided it into 100 divisions - very modern at those times. He also let the freezing point represent 100 degrees and the boiling point represented 0 degrees. It was only after his death that this was changed to what we know to be the Celcius scale of today.
The relation between inch and millimeter was discussed for many years in the NBS and the Congress. Since there were many different inces in the different states of America, it was difficult to come to a decision. Carl Edvard Johansson was a metrologist in Sweden and his principle invention were the gague blocks aka Jo-blocks after Johansson. See http://www.medibix.com/company.jsp?company_id=9992...
Henry Ford was in great need for a gauging system that could be used in all his factories. Without such a system parts from one factory wouldn't fit parts from another factory. So he asked Johansson to produce gauge blocks for him. And Johansson tried to get the numbers to work with from NBS. He never got them.
So Johansson decided to make one inch equal to 25.400000 millimeters. He delivered the gauge blocks to Ford. The rest is history.
Why proud? Well, I live in the same country as did Celsius and Johansson. And I actually worked for some time at the Johansson company in Eskilstuna.
RE: Who 'Invented' Metric
Celcius is a good example. Newton contributed a lot to relating force with mass and acceleration, and force and distance with energy; that's why Newtons, kilograms, meters, seconds, Joules and Watts can be converted back and forth so nicely. Certain funny numbers like g = ~9.8 m/s2 are funny because they are inherent properties of the earth or of other objects. Not every property of the earth can be a beautiful number when expressed in a consistent system of units. That's why the meter defined (in hindsight) as x number of wavelengths of light emitted by excited krypton gas, or a fraction y of the Earth's circumference along the prime meridian, looks as ugly as an inch being 25.4 mm. But so what..?
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
The "rounding off" took place in 1920 - 30.
RE: Who 'Invented' Metric
“Over 300 years ago, the need for a single worldwide coordinated measurement system was recognized. Gabriel Mouton, Vicar of St. Paul's Church in Lyons (France) and an astronomer, proposed, in 1670, a decimal measurement system based on the length of one minute of arc of a great circle of the Earth. Mouton also proposed the swing length of a pendulum with a frequency of one beat per second as the unit of length. A pendulum with this beat would have been fairly easily to reproduce, thus facilitating the widespread distribution of uniform standards. Other proposals were made, but more than a century elapsed before any action was taken.
In 1790, in the midst of the French Revolution, the National Assembly of France requested the French Academy of Sciences to "deduce an invariable standard for all the measures and all the weights." The Commission appointed by the Academy created a system that was, at once, simple and scientific. The unit of length was to be a portion of the Earth's circumference. Measures for capacity (volume) and mass were to be derived from the unit of length, thus relating the basic units of the system to each other and to nature. Furthermore, larger and smaller multiples of each unit were to be created by multiplying or dividing the basic units by 10 and its powers. This feature provided a great convenience to users of the system, by eliminating the need for such calculations as dividing by 16 (to convert ounces to pounds) or by 12 (to convert inches to feet).
British industry converted successfully to the metric system in the 1960s. But with continued legal validity of inch-pound units, take up of the metric system by the British public remained a slow process for three decades, which is still in progress. The pound finally lost its status as a legal unit of weight in the United Kingdom on 1 January 2000, but dual labelling will be permitted until 2009.”
I suppose that the English people will never change to the Euro, will never change to the metric system, will never drive on the right.
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
All our engineering industry has been metric for decades. I haven't seen a drawing in inches for about 30 years, except ones from the US. Ironically, they call them "English Units" in the US but that is historical.
Driving on the right? Well the Japanese do too, and they make more cars than anyone else. I know the Swedes made the change, we are more conservative than they are.
The Euro currency - it will come eventually, it's just a question of us getting used to the idea. Euros do change hands here, you can't go into Europe without them and we have a lot of Irish people (our largest immigrant community) using them.
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
At the risk of being called a heretic, why the big push for the metric system or SI or whatever the "official" name is? (Yes, I know there are technical differences but on normal human scale these are insignificant.)
I'm not trying to be a pain, but being a US engineer who has done work abroad, I really don't get why metric is easier or better. I understand the history of the metric system, but I'm still at a loss as to the supposed advantages of it.
It's supposed to be more rational. As far as I can tell, it has only two "rationalities": everything uses base 10; and the relationships between units is by design rather than coincidence. Are there more that are unknown to me?
We can discuss the various points later, but I thought I'd start with this.
Imagineer
RE: Who 'Invented' Metric
A third reason is that if the whole world uses a common system this is better for everyone. Converting between units is a pain, and a source of error.
RE: Who 'Invented' Metric
And one other reason - slugs. Need I say more?
-erica
RE: Who 'Invented' Metric
> The problem with mixed fractions is that they're MIXED. We use decimal inches in all our drawings with no problems other than normal addition and subtraction errors.
TTFN
RE: Who 'Invented' Metric
I agree with Erica....slugs.
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RE: Who 'Invented' Metric
The Nederland Pint is equal to the English pint?
Are the beer drinkers being stolen because when they ask for a pint they also pay the foam?
luis
RE: Who 'Invented' Metric
Er, on a pint beer glass there is a line near the top that marks the pint level, the liquid must reach this line and any foam is above this - and the pumps are usually push button so they dispense an exact pint.
Surely it's more efficient to drink by the litre, this means less visits to the counter, less glasses to collect and wash.
RE: Who 'Invented' Metric
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
http://www.bridgeportbrew.com/home.html
http://www.rogue.com/
http://www.redhook.com/ales.html
Seriously off-topic, I know. My apologies.
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
Brand names are not prohibited, per se, since many forum names include a brand name.
TTFN
RE: Who 'Invented' Metric
But Filtered Horse P!$$ starts with an 'F', not a 'B'.
Come to Portland Oregon and enjoy the vast variety of beers available, the majority of which are brewed within 200 miles. You could probably enjoy a different, good, beer every day all year.
RE: Who 'Invented' Metric
davidbeach - I didn't have a high quality experience but perhaps I was misusing the product. I am very confident too that suitable alternative products are available in Oregon, but unfortunately I'm scared of volcanoes.
RE: Who 'Invented' Metric
Well worth going on if you can wangle it. (Wilo Pumps in case you were interested)
Friar Tuck of Sherwood
RE: Who 'Invented' Metric
Are there any other units that are different, i.e. US gallon, (Is there a US inch or is it the same as an Imperial Inch--25.4mm)
Friar Tuck of Sherwood
RE: Who 'Invented' Metric
Doubtless there are others
Cheers
Greg Locock
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.
RE: Who 'Invented' Metric
A
RE: Who 'Invented' Metric
a long ton is an imperial ton = 2240 lbs (just about a metric tonne)
a short ton is 2000 lbs ... i guess they couldn't be bothered with the 240 lbs (maybe a comment on the education system in the US)
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
I suppose metric makes sense since we have ten fingers. There isn't much logic to counting in twelves is there?? (Or is there?)
Friar Tuck of Sherwood
RE: Who 'Invented' Metric
Start with the basic unit of 1 ft. That had some rough correspondence to a body part that's always with you, as opposed to the tape measure that's either at home or in another room.
Now you want a smaller unit, so maybe you use the length of the big toe or the thumb. It then turns out that there are roughly 12 of those to the foot.
The fact that you have 10 fingers is irrelevant, because the basic unit had a requirement to be something commonplace, and ideally, with you all the time. One-millionth of the distance from the equator to the north pole is unrealistic and unmanageable at the personal level.
TTFN
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
12 signs of the Zodiac
12 animals in the Asian calendar
Minutes arranged as 12 groups of 5
12 hours in a half-day
12 months in a year
TTFN
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
Notnats, when referring to the 12 tribes, although Moses guided them out of Egypt it was Jacob who was credited with their being born. Somehow, I entertained the illusion you'd find a divine nexus in the number 12 because of the biblical connotations.
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
RE: Who 'Invented' Metric
The common use of numbers like 12 or 16 to divide units predate the use of 10.
Despite the metric claim of 10 being more intuitive because of having ten digits on our hands, I think 12 is more intuitive. This is because people think in terms of halves, not 10th. This also
The question ,"Is the glass half full?" is never presented as, "Is the glass .5 full?" Also, dividing an inch into half, half again into 1/4, etc is very natural.
Since the metric system came from France (and the metric unit based on a measurement of the earth through France) it was an alternative to Great Brittan's world standard. I think the main motivation for metric was political, not scientific or an effort to unify units.
Joe Dunfee
RE: Who 'Invented' Metric
Cadcoke, there is a very practical reason for measuring the Earth's quadrant the way the French did it. The measurement was done along a stretch of land that included Finland, the Baltic states, Prussia, Germany, France, Spain etc. It simply wasn't practical to do precision measurements across open water, which would have been necessary if England was included in the chain. Nothing political there.
Gunnar Englund
www.gke.org
RE: Who 'Invented' Metric