KM vs Miles

[Andy in Germany]

By contrast, the foot is based on the length of the human foot. This invites the question of whose foot? Everybody is different. This led to there being (before the metric system was developed) there being dozens of different lengths of the foot for different areas and different times, varying between about 10½ and 13½ (imperial) inches.

This was a major issue here: Until the mid 1800's the next village to the south was in Prussia, my village was in Austria, and Württemberg was just up the hill: Pre metric all used different definitions of a "foot", not to mention different weights, making any trade between them a real pain.

 

[Andy in Germany]

Here I am, stood in field with the clothes I stand in. How do I use that definition to measure out an area?



Perfect, I have my measuring tools with me.

Which is fine, until your tax assessor comes along and has smaller feet, or you try to sell it to someone with bigger feet.

 

[Punkawallah]

Unless it's a very small area then you pace it, which is roughly a metre, or roughly a yard, depending on your stride length. That's much easier than putting your feet end-to-end repeatedly. And the variance between people is similar to that for feet; quite possibly less. So both systems work equally well, albeit with a 10-20% inaccuracy, for that application, though the metre has the advantage, over the yard, of not being 'three of something smaller'. And once you have your result in square metres, converting to hectares is a good bit easier than to acres!

Only for someone not used to it. An acre is one chain by one furlong (22 yards by 220 yards).
The average pace is about 30” (some 75cm in new money), 12 paces about 360” (or 10 yards).
And the meter, it must be remembered, is 10 decimetres.

 

[Punkawallah]

This was a major issue here: Until the mid 1800's the next village to the south was in Prussia, my village was in Austria, and Württemberg was just up the hill: Pre metric all used different definitions of a "foot", not to mention different weights, making any trade between them a real pain.

S’cultural, innit! ;-)

 

[Andy in Germany]

And the meter, it must be remembered, is 10 decimetres.

One of the great advantages of the metric system is that a litre, as well as being 1kg of water, is also defined as 1 cubic decimetre, which makes converting cm to volume much simpler.

 

[Andy in Germany]

S’cultural, innit! ;-)

It certainly explains why metric measurements were more reality embraced in Europe: it meant your neighbour used the same measurements as you did, so it was much easier for everyone.

Being a relatively centralised Island for a long time has affected the UK in many ways.

 

[classic33]

The metric system is based on the metre being one 10 millionth of the distance between the north pole and the equator, and the density of water (1 kg = 10cm cubed). OK, the distance isn't something that's easily measured so there was a physical standard to compare against, but they got within 0.02% of being correct with it, which is pretty good IMO.

By contrast, the foot is based on the length of the human foot. This invites the question of whose foot? Everybody is different. This led to there being (before the metric system was developed) there being dozens of different lengths of the foot for different areas and different times, varying between about 10½ and 13½ (imperial) inches.

The metre being decided on over a hundred years before the actual North Pole was ever located, and reached.
That they came close, for the measurement, was as much down to luck as anything else.

The imperial foot would have been decided by the size of the feet of whoever was on the throne at the time. Much like the Yard, distance between finger and thumb on an outstretched arm, to the nose. Given the punishments for short selling were severe back in the day, it paid to have a source to go to.

 

[Punkawallah]

It certainly explains why metric measurements were more reality embraced in Europe: it meant your neighbour used the same measurements as you did, so it was much easier for everyone.

Being a relatively centralised Island for a long time has affected the UK in many ways.

It does bring up the question of the chap who has a Bavarian neighbour on one side, and a Westphalian neighbour on the other. :-)

 

[Punkawallah]

One of the great advantages of the metric system is that a litre, as well as being 1kg of water, is also defined as 1 cubic decimetre, which makes converting cm to volume much simpler.

The point being that the yard is not the only unit that is made up of other units of measure.

 

[Punkawallah]

The metre being decided on over a hundred years before the actual North Pole was ever located, and reached.
That they came close, for the measurement, was as much down to luck as anything else.

The imperial foot would have been decided by the size of the feet of whoever was on the throne at the time. Much like the Yard, distance between finger and thumb on an outstretched arm, to the nose. Given the punishments for short selling were severe back in the day, it paid to have a source to go to.

And the meter is the distance between the outstretched arm and the ear ;-)

 

[classic33]

And the meter is the distance between the outstretched arm and the ear ;-)

In which case, it'd come up short of yard, by around 2"- 4".

 

[Ming the Merciless]

That they came close, for the measurement, was as much down to luck as anything else.

Not really. You just have to come up with a fairly accurate measure for the curvature of the Earth. Then extrapolating to the circumference, and distance from equator to poles etc is fairly straight forward.

 

[Dogtrousers]

All this bickering over which is a "better" system is plain silly.

For science, engineering and technology there is only one system choose: SI. There simply is no coherent system for imperial/customary units, just a fractured patchwork of options. See my post above on the subject of slugs and poundals.

But for everyday use, you should use whatever is most convenient for you, and the audience with which you wish to communicate.

So if you're posting in the imperial century a month thread, you will not post that you have just completed a 170km ride. To do so would be to be wilfully obtuse.

Similarly if you are posting in the Your Next Audax thread you don't say that you're looking forward to entering the "So & So 124.28" when everyone else knows it as the "So & so 200" unless you are trying, and failing, to be clever and funny.

Or if you're posting in the pro cycling forum about stages in the Tour de France, you wouldn't say a particular mountain stage looks hard because it has X feet of climbing, because pro races are discussed in metric so your X would need to be converted to metres to have any relevance.

The original basis of the metre in relation to the size of the earth is historically diverting but not of any practical relevance. The metre these days is defined in terms of the speed of light, which in turn relies on the definition of the second as some Cesium vibration thingy to be measured. These are fundamental constants of nature. The yard shares this same basis, as customary units are only defined in terms of their SI counterparts.