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.