Does anyone use grads instead of degrees or radians 1

[xwb]

My very first calculator 25 years ago had a DRG button. That's the first time I heard of grads - 100 grads = 90 degrees. I've yet to meet someone who's actually used them. When I was in Uni, we were told that it is used in Europe but I've never met any European engineers who were educated in grads: they were all educated in degrees or radians. All the European text books I've seen for Maths are in degrees.

Almost every calculator supports grads but I haven't seen a single computer program that uses grads. I've seen mils for measuring angles but I've never seen grads.

If, like they say, the Europeans use grads, there should be a grad version of the globe but I've yet to see one of those.

So the big question is: does anyone out there use grads?

 

[IRstuff]

Theodolites still have grads, disguised as "gons." They're also the only place I know that uses "sexagesimal"

TTFN

 

[Skogsgurra]

European compasses have 400 divisions around the perimeter. I guess that is the same thing as "grads". BTW, "one degree" = "en grad" in Swedish. But that doesn't mean that "en grad" = 1 grad, it still is one degree.

Is the grad a military thing?

Gunnar Englund

http://www.gke.org

 

[xwb]

I'll have to keep a look out for a European compass the next time I go there.

Grads (grades) is one of those French Revolution/metric things like metres, grams, litres, joules, metric weeks etc. Napolean got rid of the confusing ones like the 10 day week but he kept metres etc.

The military measurement is mils but it depends on whether it is US mils or Russian mils. 1 circle = 6400 US mils = 6000 Russian mils. See

http://www.boomershoot.org/general/mils.htm

for the stories.

On the great Atlantic divide, I've yet to find a calculator that converts litres to UK gallons. They all seem to convert to US gallons which throws my mpg calculations out.

 

[nbucska]

If multiplying/dividing by .9 is too difficult I think
you are beyond help...

<nbucska@pcperipherals DOT com> subj: eng-tips
read FAQ240-1032

 

[xwb]

Multiplying/dividing by 0.9 may not be much of a problem but try teaching kids that the internal angles in equilateral triangles are 66.66 is not so easy.

On the plus side for grads, N=0, NNE=25, NE=50, ENE=75 and E=100 is a lot easier than N=0, NNE=22.5, NE=45, ENE=67.5 and E=90.

However, if we do not keep to one system, however good or bad, we could end up with the crash that happened a few years back where the pilot was told the height in feet and he thought it was in metres.

 

[Skogsgurra]

It was only two weeks ago that xwb asked about gons (the 400 grad instead of 360 degree system).

I collect slide rules. For many reasons; they are fine little pieces of craftmanship, they carry engineering history with them, they are an extinct breed, they are (still) quite affordable and the late ones are real beauties - the Faber, Hemmi and Aristo works tried to meet the competition from electronic caculators by introducing colour and smart design details, but in vain.

I found one with grads yesterday. It is a Faber-Castell 67/38b with a 400 grad system instead of the usual 360 degrees. It has the nickname Tachymeter and was clearly used in surveying.

So, there's another use for 400 grads: Surveying

Gunnar Englund

http://www.gke.org

 

[xwb]

I've got a Faber-Castell too but it doesn't have grads. It is a small 8" one which I only use for currency conversions nowadays: faster than a calculator and never needs batteries!!! The circular ones are more compact but they don't sell them anymore.