What's it called ??

[Bluechip]

What is the proper name for the  ( roughly ) triangular bit that tops a set of columns?

Usually has the ends chopped off.

Greeks and Romans used to knock 'em out by the dozen for their buildings.

Damned if I can remember it ...   

Dave

[Jasonb]

Pediment

[Bluechip]

Pediment

Cheers Jason ... 

My miserable little brain was locked in a loop of 'pedestal & portico' and I knew neither are right .. 

Dave

[Johnb]

You clearly had an im-pediment to your memory 

[Bluechip]

You clearly had an im-pediment to your memory 

What's a memory ?     

I only started out with 8k of core and most of that's knackered now.     

Dave

[Lew Hartswick]

I'm not so sure about that if the language hasn't been butchered up.
< Pediment >   The Ped part means  foot  so I'd suspect that is for the  "thingy" at the bottom of the column.
   ...lew...

[mklotz]

I'm not so sure about that if the language hasn't been butchered up.
< Pediment >   The Ped part means  foot  so I'd suspect that is for the  "thingy" at the bottom of the column.
   ...lew...

And you would be wrong.  See...

http://www.dictionary.com/browse/pediment?s=t

Your  (gag) "thingy" is properly called a 'plinth'.

[paul gough]

 Greetings from Thailand, first chance to use the internet for a while, If you are enquiring, (architecturally), about the very top flat bit that another element sits on then it would be called an ABACUS, otherwise in more general terms the whole top piece is usually referred to as the CAPITAL. Regards, Paul Gough.

[Jasonb]

There is a clue in the question "tops a SET of columns"

Abacus and capital are found at the top of a single column

[paul gough]

Thanks for pointing out my blindness for the plural Jason, my old mind misapprehends far too frequently now, of course the whole triangular structure is a pediment. Appologies for wasting peoples time. Regards, Paul Gough.

[Jo]

I wish you lot hadn't started this. 

I suddenly felt the need to go and visit my favourite building in the whole world only to find that my last passport ran out three days ago .

Jo

[Bluechip]

I wish you lot hadn't started this. 

I suddenly felt the need to go and visit my favourite building in the whole world only to find that my last passport ran out three days ago .

Jo

What! Passport to get into the Workshop now??

I'm most impressed ... 

( Or, perchance, Buck House ? Dame-hood in the offing ?     Well deserved if I may say so.  )

Dave

[Lew Hartswick]

I'm not so sure about that if the language hasn't been butchered up.
< Pediment >   The Ped part means  foot  so I'd suspect that is for the  "thingy" at the bottom of the column.
   ...lew...

And you would be wrong.  See...

http://www.dictionary.com/browse/pediment?s=t

Your  (gag) "thingy" is properly called a 'plinth'.

Well Marv,  <  Geology. a gently sloping rock surface at the foot of a steep slope, as of a mountain, usually thinly covered with alluvium. >
included in the above reference.  As well as the entire region in Virginia east of the mountains " Pedmont" . :-)  So just another misuse of a Latin prefix that has been in use for quite a while, I guess.  :-)
   ...lew...

[Mosey]

A sketch or drawing might be helpful, but if you mean the triangular end of a columned building, or the triangular end of an attic, it would be a Pediment or Gable. Plinth is incorrect, as that is a flat slab base under a column, pedestal, or statuary.
Mosey

[mklotz]

  As well as the entire region in Virginia east of the mountains " Pedmont" . :-)  So just another misuse of a Latin prefix that has been in use for quite a while, I guess.

No, that's the Piedmont, not the "Pedmont".

[mklotz]

A sketch or drawing might be helpful, but if you mean the triangular end of a columned building, or the triangular end of an attic, it would be a Pediment or Gable. Plinth is incorrect, as that is a flat slab base under a column, pedestal, or statuary.

No one has suggested that "the  ( roughly ) triangular bit that tops a set of columns" mentioned by the OP is a plinth.  Lew tried to describe the base of a column as a "thingy" and I pointed out it's properly called a plinth.

[Jasonb]

Ped does have its use when talking about columns as a Pedestal is often found at the bottom of a column below the base. Think of the pedestal as a round or square block that the column sits on. But a pedestal is not a pediment.

Base of a column is called a base. This is usually the decorative part

[Jasonb]

I

I suddenly felt the need to go and visit my favourite building in the whole world

So Jo does this building have stone colunms or Cast Iron Columns?

[Jo]

So Jo does this building have stone colunms or Cast Iron Columns?

The pronaos has 16 monolithic columns in grey and pink granite, topped with Corinthian marble capitals, crowned by a tympanum pediment   

Edit: while it does not have any true casting it has stunning coffering on the rotunda    which when you know how it was done I think it counts as being as good as if it was cast 

Jo

P.s. Some  nicked the bronze frieze from the pediment to make some cannons