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Thumb rule?

Thumb rule?

Thumb rule?

(OP)
Where and how did the expression "thumb rule" arise instead of "rule of thumb"?  I see it more and more often these days, and it can be a bit off-putting.

Bung
Life is non-linear...

RE: Thumb rule?

I like using the term "heuristic" but no one else seems to like it.  I've never heard "thumb rule", but now that you've said it, I think I'll use it.

RE: Thumb rule?

From my understanding, the "rule of thumb" was used as an approximate measurement since the thumb is about an inch long.  From that, the 'rule of thumb' became, over time, a general guideline.

I don't know, but it might be that the phrase was 'rule of thumb' and not 'thumb rule' because of traditional possessive rules, and that thumb is not an adjective.

Traditionally, the possessive construct could only be used on things that could actually own something.  You can have 'the man's car' but not 'the computer's monitor' because a computer cannot own a monitor.  The correct grammatical construct would be 'the monitor of the computer'.  Therefore, since the thumb itself is not capable of owing something, the proper phrase would be the 'rule of the thumb', and with the dropping of the definite article for the purposes of generalization, the 'rule of thumb'.  Today, possessive rules are far more lax, so it would be acceptable to say 'thumb's rule'.

It also more acceptable today to use nouns as an adjective, thus removing the possesive state to get 'thumb rule'.

Again, I don't know.  What are some other thoughts?

Good Luck
--------------
As a circle of light increases so does the circumference of darkness around it. - Albert Einstein

RE: Thumb rule?

From my understanding, the "rule of thumb" was used as an approximate measurement since the thumb is about an inch long.  

That'd be a tiny thumb.  Mine are each about an inch wide, and closer to 3 inches long (no scale handy).  

http://dynamic.uoregon.edu/~jjf/essays/ruleofthumb.html
Like many folk etymologies, the commonly understood origin of "rule of thumb" seems to have some inaccuracy. The Oxford English Dictionary indicates that the phrase has been used for about 300 years to refer to measurements that are based on experience instead of exact science. However, some people currently believe that the phrase "rule of thumb" originated from English common law, and that the phrase reflects a law which allowed a husband to beat his wife with a whip or stick no bigger in diameter than his thumb...
In America he cites a North Carolina case, State v Rhodes, 1868 61 N.C. 453, as "the only case on record in which a husband was let off because 'His Honor was of opinion that the defendant had a right to whip his wife with a switch no longer than his thumb.'" [Kelly, p. 345]. The State Supreme Court repudiated this argument but dismissed the case on the basis that the husband had not actually harmed the wife substantially. In other words, the rule of thumb was illegal, but wife-beating was legal as long as it didn't inflict much permanent damage.
We caution readers to use restraint in judging others harshly for either their use of the phrase "rule of thumb" or for their pain in hearing the phrase used and believing it refers to domestic violence. Keep in mind that folk etymologies are very often incorrect, and deriding people for a false belief in this area serves little purpose.

RE: Thumb rule?

I guess I should add that I've always heard "rule of thumb" used to describe general solutions or anwers to common problems/questions (heuristics, etc).  I've occasionally heard "thumb rule" used to describe a method of evaluating the importance of an item on a drawing, in which one covers the item with his thumb and then decides whether the meaning of the drawing has changed.  The latter is not a very common usage, as far as I can tell.

RE: Thumb rule?

Ivymike:  The wife-beating origin of the phrase has been pretty much debunked, though your cite points out it doesn't really matter much one way or t'other.

For many people the first (or is it last?) joint of the thumb is about an inch long, not that I'm saying that's the definitive origin either.

CajunCenturion:  Nothing grammatically wrong with "thumb rule"--modifiers don't have to be adjectives.  Ever eat apple pie?  This is hardly a modern innovation.

That said, I agree it sounds weird when there's such an established phrase as "rule of thumb".

Hg

Eng-Tips guidelines:  FAQ731-376

RE: Thumb rule?

Surely the 'thumb rule' is never to hitch hike in front of a bus?

corus

RE: Thumb rule?

Why? Because you'll get tired?  If you are behind the bus, you'll get exhausted.

RE: Thumb rule?

(OP)
So it would seem that I am in a bit of a minority in finding the "thumb rule" jarring to the ear (as opposed to "rule of thumb".  It may be grammatically correct, but it doesn't sound "right' to my ear!

BTW it has always been my understanding that the inch measure comes from the top joint of the thumb.  I have small hands by any standard, and the top joint of my thumb is well over inch long, so people must have been very small in days of yore!

Bung
Life is non-linear...

RE: Thumb rule?

I have only heard "thumb rule" used by people whose first language is not English.

I've always assumed it was just something lost in translation.

RE: Thumb rule?

(OP)
Yes, MintJulep, now you mention it, in my experience it does seem to be used more by people from the Indian subcontinent so it is probably just another case of external influences changing the language.

Bung
Life is non-linear...

RE: Thumb rule?

...then I will jump in. Firstly, beating wives is never official in Inida so I will rule this out. I didn't see unofficial incidences either, so far.

The linear movement of a screwed fastener follows the direction of thumb when it is rotated in a direction pointed by other fingers.

Regards,

RE: Thumb rule?

In Inida, thumb rule is also used by tractor engineers. You push the fan-belt of the engine by your thumb and if it deflects more than 1", it needs tightening.

Ciao.

RE: Thumb rule?

I used to referree novice house league hockey games at the community center.

The Thumb Rule referred to the amount of space allowed by the curve of the blade - if the space between the blade (stick laid flat) and the ice was wider than your thumb, then there was an "illegal curve" to the stick... Gives you a wicked wrist-shot, though.

RE: Thumb rule?

Place a thumb on a flat surface and scribe a line either side, the width is about an inch. Useful I reckon, if someone was making a series of marks.

RE: Thumb rule?

We metric guy's thumbs are useless anyway!

Ciao.

RE: Thumb rule?

Come to think of it the metric system got started by Napoleon's mob. They decided the linear benchmark would be the distance from Paris to the equator divided by XXXX and called it the metre. (I'm on my second glass of wine, somone else can work it out ) Using that kind of lunatic rationale the rule of thumb has credentials and deserves respect.

RE: Thumb rule?

(OP)
Does the variant of the rule raised by quark refer to special classes of thumb rule ie RH thumb rule for most normal threads, and LH thumb rule for some gas threads or the wheel nuts on the LHS of some cars?

Bung
Life is non-linear...

RE: Thumb rule?

hehe... This is a classical case of applying the rule after you complete the work.

Actually I was a bit narrow minded while defining it. How about this? I win - Thumbs Up, I loose - Thumbs Down(not subjected to engineering alone)

Regards,

RE: Thumb rule?

The subject is interesting to us EFL (English as a Fifth Language) guys. Never heard of "thumb rule" and don't care about it anyway. I have discovered the only technical application for my thumb when I slammed it with a hammer while nailing the picture to the wall. My accident review report showed that I have mistaken centimeters for inches. Some women do it too. Lucky guys, who get all that credit.

Putting Human Factor Back in Engineering

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