At the time they were the most innovative stained glass windows one can ever find, because La Farge was the first person to EVER conceive of using opalescent glass in windows (!) Before that opalescent glass was used strictly for tableware, and John La Farge had to pay a local glass manufacturer to custom-make opalescent glass in sheets for him to use. If you are a stained glass connoisseur or a stained glass crafter, you may be amazed to learn that these intricate window panels have NO Tiffany (or copper foil) in it. The entire piece is leaded with the thinnest lead I would ever have dared of using and I do not even want to imagine the hours it took to bend that came around the tiny glass pieces.
Look at the use of opalescent glass in this close up. Another remarkable thing that can be observed in La Farge windows is layering of two pieces of glass on top of one another. It is pretty widely used now, but back then it was a very novel idea. Not only does it add depth to the image, but I think another added benefit is that, one can use an opalescent glass that would otherwise strike in the kiln. For those stained glass enthusiast who do not paint - some types of glass, especially opalescents, but some cathedrals too, tend to change color and even become completely opal when heated to a high temperature, therefore rendering them impossible to use for painting. La Farge likely went around that issue by painting on a clear or tinted transparent glass and layering it on top of the opalescent color - problem solved!
If you cannot stand rebar as La Farge clearly did, we have so much more in our arsenal now, such as restrip that can be hidden inside the seams, for example. Although I personally trust the rebar a lot more for larger projects. If incorporated in the design properly, the eye will always miss the unsightly rebar when looking at the finished window. Most of the time leaving it out is just not worth the risk of having the window buckle under its own weight in 5 years. Vanderbilt may have had the money to shell out for such repairs, but our regular consumer usually does not. And in any case, if it starts moving and cracking too soon, I would feel compelled to fix it for free, because it would have been my studio's responsibility to produce a stable product. But geniuses like La Farge are exempt from such judgment, of course!
In 1992 two NJ artists were entrusted with restoring 8 of the La Farge windows, which included fixing the cracks and flattening the bowed part. They too complained of the difficulty to work with those windows due to lack of appropriate support, tiny pieces and thin lead came and the fact that these windows reside in hot NC sun now, which does a number on soft lead came. The lightly reinforced windows did alright in NY where they were originally installed, but once in the South, started bowing almost immediately. So as a result, part of the restoration project was installation of thermal insulation units that would protect the windows from the NC heat, eliminating the threat of lead getting soft and bowing again in the near future.
So I think I will continue to reinforce my windows within an inch of their life till I achieve La Farge's level of genius. :) I think ,however, that the ever so slightly flawed perfection of these windows teach us one important lesson - do not be afraid to innovate, try new things, new techniques. Innovation is never nice and tidy, there are always mistakes and things to improve on, but there is no reason not strive to achieve something greater than has been done before! You may be the new La Farge, or Tiffany! So create on!!!