Dear JazzO: in the latest issue of Smithsonian magazine there is an article about Boss Tweed, and the renovation of the big Courthouse he had built: p. 90, center column:

".....28-foot-high ceilings. A spectacular laylight with flowers, birds, frogs and squirrels painted on amber-,ruby-,and emerald-tinted glass has been replicated based on fragments of the original window

I found several sites that mentioned "laylights" but did not give a clear idea of what they are. Please enlighten us.

Hmm, I wish I could. Keep in mind I'm by no means an architectural expert yet. I'm only in my second quarter.

I checked the glossary in my huge art history text and laylight wasn't mentioned, but based on the context of the Smithsonian article and the results of a Google search, it sounds as though it's something like a stained glass window in a ceiling.

I have the magazine, so if I remember, I'll ask my art history prof on Tuesday.

Dear JazzO: My guess is that it is a big overhead horizontal window, a skylight. But how could it stay watertight, or hold a heavy snow load?

I agree, dr. bill, that stained glass would not make a good structural component. But a stained glass window could function as you describe without being a structural component, without having to support any weight of snow. Simply put a skylight (or severaly adjacent skylights) in the structural roof, and place the stained glass just below the skylight(s).

my building (but not my office) over look the Tweed courthouse (the renovations have had almost as many cost overruns as the original construction!) and it does not have a sky light.. but it has an interesting roof, with many windows in the gables-- (the gables are purely part of the roof, and don't relate to the building shape, they are hard to see from the street, but very evident from the 23 rd floor. most of the roof is standing/seam metal--the original was copper, i recall, but now its some white metal, galvanized steel? aluminum? i don't know..

the NY customs house (now part of the Smithsonian, one of 3 smithsonian building not in DC,) does have a stained glass sky light, above it, it has a peaked glass roof, (think of a greenhouse) the second roof protects the stained glass from water, but still lets in sunlight.

the smithsonian was responsible for renovating the customs house, and it now houses the Musuem of the American Indian collection. (did i mention i am a museum fan?)

it, too, is a beautiful building. Jazzo, you'd love NY!-- a hop, skip and jump from the Tweed court house is the Woolworth building.. its been all spiffed up too, and now days, looks like a skyscaper again, and is a dominant building in the downtown skyline.

I found several sites that mentioned "laylights" but did not give a clear idea of what they are. Please enlighten us.

What would a architect know about a wonderful historical building feature like a laylight? If it ain't titanium, they don't want to hear about it![/sarcasm]

A laylight is a decorative (stained glass or otherwise) window set into the ceiling of a room directly below a skylight. The sturdy skylight takes any load and the laylight is purely aesthetic. There is a wonderful set of laylights at the Vermont State House, one pane of which was literally shattered into hundreds of tiny pieces while the window was in storage. When the room was restored, a determined conservator pieced the entire thing together like a jigsaw puzzle (for which he didn't have a picture to guide him) and joined it all with epoxy. Now you can hardly tell which of the four panels was the broken one unless someone points it out.

F. Lander, Historic Preservationist

Thanks for clearing it up Flatlander. It sounds like a great idea - oh to have cathedral ceilings instead of the eight-foot flat ones [sigh]

Flatlander, how big is a typical laylight, and do you know if there any practical limit beyond which the weight of the glass itself requires that it be divided into several panels? For example, could one have a laylight the size of an 10' by 12' room? I know one can have a vertical stained-glass panel that size, but could one be used horizontally as a laylight?

Dear Flatlander: the laylights in buildings constructed before the advent of electric lights have a pleasant aesthetic effect. But for new buildings they would be impractical.
As for titanium, don't knock it. Until now it has not been much used in buildings, because it is expensive, and has fabrication limitations. But a short time ago there was an article in New Scientist about a new refining process which could reduce price allegedly by as much as seventy five percent. That could greatly increase its use.. I wonder if it can readily be made into doors and window frames.Most likely use would be for roofs, because it is light and corrosion resistant.

dr. bill, I think Flatlander was probably referring to Frank Gehry's flowing titanium Guggenheim in Bilbao, Spain . . . or the Experience Music Project in Seattle, or his new building in Germany . . .

Gehry designed the Vontz Center for Molecular Science on the UC campus. He wanted to make that titanium too, but the administration had a few budget problems with that. Gehry is bar none the most famous and most successful architect right now. on 60 Minutes Phillip Johnson (the godfather of architecture right now) said that Gehry was better than anyone else in the 20th century, including Frank Lloyd Wright. Gehry said he got his ideas from the folds and contours of a mother's clothing while holding a baby.

Also, my computer is titanium.

Flatlander, how big is a typical laylight, and do you know if there any practical limit beyond which the weight of the glass itself requires that it be divided into several panels?

Well, there is never any such thing as typical in historic buildings, but I expect the size would only be limited by the strength of the framing. If you look at large stained glass windows you'll see some pretty thick support members, generally running horizontally across the window. [Word-related]The framing around each pane of stained glass (historically made of lead, now probably copper or something else) is called the came. For a stupendously big laylight I guess you could suspend it from above at key places to provide extra support, but you would need to divide it into several frames. I should add that I've never seen a "stained glass" laylight (as in individual single-colored panes of glass) -- they are more commonly painted, etched or frosted.