Measurement - Imperial v Metric

The value of electrical units were decided the early days of electricity so when it came to electronics with lower currents etc the units were all far too high (or, in the case of resistance, low) and so lead to all the prefixes for current, capacitance, resistance, etc that Slim mentions. When I was still in the electronics servicing trade in the mid 80's some engineers thought that this was a ridiculous situation and so wanted to "invent" new units based on 1 kilohm for resistors, 1 milliamp for current and 1 microfarad for capacitors - each being equal to one of the new units (plus various others for other units) but with electrical engineers still using the original units (and, of course, some prefixes would still be needed). Fortunately this never got off the ground as the confusion it would produce would be horrendous, plus all the text books and circuit diagrams would need to be rewritten. In this case common sense did actually win out

That reminds me: the farad (F) being unwieldingly large for most applications in electronics, even power electronics, the microfarad was the most commonly used unit:

That's the way I've always labelled them as well, Slim - the symbol tells you what the units are, so no need to write them down,

Google converter is your friend 1 US cup is 0.236588 of a litre. Almost off topic but related to measurements of sort - the other day there was a programme talking about sailors' grog, the source of the word groggy. The recipe is thus - one of sour, two of sweet, three of strong, four of weak. The sour was limes, the sweet was honey, the strong was rum and the weak was water. The way the navy got the limes into the sailors to prevent scurvy and an alternative to the beer people drank at the time, that didn't travel well.

The saga of Imperial v metric goes on. Cine film sizes are always 8mm, 16mm, 35mm, or whatever. (Interestingly, Kodak, an American company, is said to have introduced 35mm in the thirties; I'm surprised they didn't call it "inch and half".) But a piece of filmage, whatever its length, is referred to as "footage". There's consistent for you. (Note the modern trend of ending as many nouns as possible with the suffix "-age"; e.g. it used to be traffic signs or road signs; now, it's signage. Uggh.) Take bowls, an old English game. If a shot is short in length, the player needed "another foot of weight". A good shot is congratulated with "good wood!". (The horse racing fraternity uses the same expression: I heard one aficionado say he was "going to good wood". No doubt Kaga will confirm this.) Then there's the railroad (railway to the English). The most common track gauge is the standard gauge, which is in feet and inches. It's all over Europe, even Germany, and many other metric countries.

Slim, You might find that standard gauge is 1435mm in several countries (including the UK - officially). A distance can be measured in any units. In the UK, being between the rails is described (officially) as "in the four-foot" - not a good place to be. Between tracks is the 'six-foot' (not much better if there are trains coming - lie down). Peter.

Hi Slim I'm not sure if you're pulling our legs with reference to "going to good wood" - is it possible they just meant Goodwood Racecourse?

Yes Peter. I'm sure this country defined it first, in the early 19th century (Stephenson), and labelled it in feet and inches. I guess it's later been converted into mm. 1435 is an awkward number. If you were starting in metric you'd have 1500mm (like the old 5ft fluorescent being called 1500, the 6ft called 1800 etc). "The distance between the inside edges of the rails is defined to be 1435 mm except in the United States and on some heritage British lines, where it is still defined in U.S. customary units as exactly "four feet eight and one half inches." "In the six foot" reminds me of those old black and white films with an innocent girl and the bad guy!

Hello 3Spires. Sometimes, as we hurtle through space, as some scientists posit, on a meaningless piece of rock, some humourage is propitious.

Interesting (?) article here - some of the comments at the end are worth a read

The one I like is rods and perches, wonder where they got those measurements from?

Recall those from schooldays - rod, pole, perch...

I know that this is from the sometimes unreliable Wikipedia but here is an explanation that seems plausible. Rod, pole and perch origins

Old Lincolnian That's brill, thanks. It did come into the old farm life in early days, so once again thanks.

Starting one's apprenticeship in 1970 probably amounted to an advantage. I have a selection of micrometers and vernier calipers in SI and Imperial units, so measure in thousands of an inch or hundredths of a millimetre depending on which comes to hand. I never, ever refer to the devil centimetre though. Perish the thought.