Pediments are the arched designs that top buildings, windows, or doors, typically in the form of shallow triangles, while broken pediments are open at the top where the two angled sides would meet.

The city's most famous broken pediment is atop the Sony Building at 550 Madison Ave. Philip Johnson made newspaper front pages when he designed it for the original owner, AT&T. The building is sometimes referred to as having a Chippendale top, a reference to the 18th-century English furniture designer Thomas Chippendale.

The Bank of New York has a very attractive broken pediment above the entrance to its handsome Federal-style low-rise at 909 Madison Ave., at 73rd Street. An eagle with spread wings is about to lift off from the "swan's neck" broken pediment at the circa-1931 building, designed by Schultze & Weaver.

There are two other broken pediments worth ogling on East 73rd Street. One is on the wonderful apartment building at 775 Park Ave., which has an abundance of broken pediments boasting small urns above the entrances to its four maisonettes. The 13-story building, completed in 1927, was designed with Italian Renaissance-style detailing by Rosario Candela.

Down the block, at 123 E. 73rd St., is a handsome neo-Georgian-style townhouse designed in 1903-4 by Robertson & Potter. The middle of the three windows on the third floor has a broken pediment and what appears to be the remnant of a support for an object in the opening.

In SoHo, there are ferocious lions bursting from broken pediments atop the 1889 Charles Broadway Rouss Building, designed by Albert Zucker at 555 Broadway.

The most extraordinary "stuffed" broken pediment can be found above the entrance to the red-brick apartment building at 4 E. 88th St., which was erected in 1922 and designed by Electus D. Litchfield & Rogers.

In his fine book "Touring the Upper East Side, Walks in Five Historic Districts," Andrew S. Dolkart suggests that one of the small carved heads inside the broken pediment is "clearly George Washington, peering off into Central Park." It's hard to find George Washington in this spiffy group that is bunched together in almost surrealistic, bodyless fashion, dominated by a fellow wearing a top hat who perhaps is none other than Litchfield. The architect served for a while as president of the Municipal Art Society and was clearly attuned, as all should be, to whimsical urban enchantments.