THE Streetscapes column is not big on terminology, but some is necessary; instead of embarrassing yourself by saying “those grooves on the side of a column,” impress your dinner partner and use the real term, fluting. FLUTING This is an apt term for shallow vertical channels, usually in a column; where else would you leave your flute? There’s a whole mess of fluting out in Morristown, N.J., where scores of column drums of Westchester marble, salvaged from a demolition site a century ago, lie strewn around like a collapsed project of wooden blocks. Some of the best fluting in New York is not on a column at all, but the first-floor wall of the estimable 740 Park Avenue. The low, almost flat curves evoke the currents and eddies on the sea bottoms where this limestone was formed. ORIEL OR BAY? We are speaking of those picturesque bumplike things on a facade, almost always with windows. Sometimes they continue all the way to the ground, sometimes they float in midair. Here’s the trick: does it rest on its bottom? Then that’s B, for bay. Or, does it stick out from a higher floor on the facade with nothing under it? That’s O for oriel, with zero underneath. There are some great oriels...